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%\newcommand{\macx}[2]{%
%  \phantomsection\pdfbookmark[subsection]{#1}{#2}#1}

% This is alchemy but good enough for now.
\newcommand{\macrodef}[5]{\paragraph*{\hfill}\noindent%
  \phantomsection\pdfbookmark[subsubsection]{#1}{#2}\hspace*{-\parindent}%
  \setbox\Defbox=\hbox{\tt #1#3}%
  \ifdim\wd\Defbox>\textwidth%
    \setbox\Defbox=\hbox{\parbox[t]{\textwidth}{\tt #1#3}}\fi%
  \nopagebreak%
  \ifdim\wd\Defbox>\leftwid%
    \box\Defbox\hfill\break\hspace*{-1ex}\hbox to \leftwid{\hfill}%
  \else\hbox to \leftwid{\box\Defbox\hfill}\fi%
  \hbox to \libwid{#4\hfill}%
  \begin{minipage}[t]{\rightwid}\raggedright#5\end{minipage}}%

\newcommand{\seesect}[1]{ (\SR{#1})}

\newcommand{\Letter}[1]{\noindent%
  \pdfbookmark[subsection]{#1}{#1}%
  \hskip-2em\hbox to 2em{\par#1\label{#1}}\relax}%

\newcommand{\LR}[1]{\hyperref[#1]{{#1}}\hskip1em}
\newcommand{\fra}[1]{\hbox{\sl frac#1}}%
\renewcommand{\Re}{\mathop{\rm Re}\nolimits}
\renewcommand{\Im}{\mathop{\rm Im}\nolimits}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%\raggedbottom
\vspace{\abovedisplayskip}
\noindent
\LR{A} \LR{B} \LR{C} \LR{D} \LR{E} \LR{F} \LR{G} \LR{H} \LR{I} \LR{J}
\LR{K} \LR{L} \LR{M} \LR{N} \LR{O} \LR{P}
\LR{R} \LR{S} \LR{T} \LR{U} \LR{V} \LR{W} \LR{X} \LR{Y} \LR{Z}
\\

\Letter{A}%
\macrodef{above\_}{above_}{}%
  {gen}%
  {string position above relative to current direction}%
\macrodef{abs\_}{abs_}{({\sl number})}%
  {gen}%
  {absolute value function}%
\macrodef{ACsymbol}{ACsymbol}{(at {\sl position, len, ht,} %
  [n:][A]U|D|L|R|{\sl degrees}) }%
  {cct}%
  {draw a stack of $n$ (default 1) AC symbols
   (1-cycle sine waves); If arg 4 contains A, two arcs
   are used.  The current drawing direction is default, otherwise Up, Down,
   Left, Right, or at {\sl degrees} slant; \seesect{Twoterminal:} e.g.,\\ 
   {\tt ebox; $\lbrace$ACsymbol(at last [],{,}dimen\_/8)$\rbrace$}}%
\macrodef{adc}{adc}{({\sl width, height, nIn, nN, nOut, nS})}%
  {cct}%
  {Analog-digital converter with defined width, height, and number of
   inputs {\tt In$i$}, top terminals {\tt N$i$}, ouputs {\tt Out$i$},
    and bottom terminals~{\tt S$i$}}%
\macrodef{addtaps}{addtaps}{([{\sl arrowhd}%
  | type={\sl arrowhd};name={\sl Name}],
    {\sl fraction, length, fraction, length,} $\cdots$)}%
  {cct}%
  {Add taps to the previous two-terminal element.
   {\sl arrowhd} is blank or one of {\tt . - <- -> <->}.
   Each fraction determines the position along the element body of the tap.
   A negative length draws the tap to the right of the current
   direction; positive length to the left.
   Tap names are Tap1, Tap2, $\cdots$ by default  or
   Name1, Name2, $\cdots$ if specified 
   \seesect{Composite:}}%
\macrodef{adjust}{adjust}{([at {\sl position}], {\sl keys})}%
  {cct}%
  { Ajdustment screwhead in a [ ] block.
   {\sl keys:}
    {\tt size={\sl expression;}}
    {\tt angle={\sl degrees;}}
    {\tt slotwid={\sl expression;}}
    {\tt circle={\sl attributes;}}}%
\macrodef{along\_}{along_}{({\sl linear object name})}%
  {gen}%
  {short for {\tt between {\sl name}.start and {\sl name}.end}}%
\macrodef{Along\_}{Along_}{({\sl LinearObj,distance,}[R])}%
  {gen}%
  {Position arg2 (default all the way) along a linear object
   from {\tt .start} to {\tt .end}
   (from {\tt .end} to {\tt .start} if arg3={\tt R}) }%
\macrodef{amp}{amp}{(\linespec, {\sl size}, {\sl attributes})}%
  {cct}%
  {amplifier\seesect{Twoterminal:}}%
\macrodef{And, Or, Not, Nand, Nor, Xor, Nxor, Buffer}%
 {And, Or, Not, Nand, Nor, Xor, Nxor, Buffer}{}%
  {log}%
  {Wrappers of {\tt AND\_gate}, $\ldots$ for use in the {\tt Autologix}
   macro}%
\macrodef{AND\_gate}{AND_gate}{({\tt {\sl n}, [N][B],
   [{\sl wid}, [{\sl ht}]], {\sl attributes}})}%
  {log}%
  {`and' gate, 2 or {\sl n\/} inputs ($0 \leq n \leq 16$) drawn in the
   current direction;
   {\tt N}: negated inputs; {\tt B}: box shape.
   Alternatively, {\tt AND\_gate({\sl chars}, [B], {\sl wid},
    {\sl ht}, {\sl attributes})}, where
   arg1 is a sequence of letters {\tt P|N} to define
   normal or negated inputs.
    \seesect{Logicgates:}}%
\macrodef{AND\_gen}{AND_gen}{($n$, {\sl chars}, [{\sl wid}, [{\sl ht}]],
  {\sl attributes})}%
  {log}%
  {general AND gate: $n$=number of inputs $(0\leq n\leq 16)$;
           {\sl chars:}
           B=base and straight sides; A=Arc;
           [N]NE,[N]SE,[N]I,[N]N,[N]S=inputs or circles;
           [N]O=output; C=center.
   Otherwise, arg1 can be a sequence of letters {\tt P|N}
   to define normal or negated inputs; arg2 is as above except that
   {\tt [N]I} is ignored. Arg 5 contains body attributes.}%
\macrodef{AND\_ht}{AND_ht}{}%
  {log}%
  {height of basic `and' and `or' gates in {\tt L\_unit}s, default 6}%
\macrodef{AND\_wd}{AND_wd}{}%
  {log}%
  {width of basic `and' and `or' gates in {\tt L\_unit}s, default 7}%
\macrodef{antenna}{antenna}{%
  (at {\sl location}, T, A|L|T|S|D|P|F, U|D|L|R|{\sl degrees})}%
  {cct}%
  {antenna, without stem for nonblank 2nd arg; arg3 is\\
    {\tt A}: aerial (default),\\
    {\tt L}: loop,\\
    {\tt T}: triangle,\\
    {\tt S}: diamond,\\
    {\tt D}: dipole,\\
    {\tt P}: phased,\\
    {\tt F}: fork;\\
    arg4 specifies Up, Down, Left, Right, or angle from horizontal (default 90) 
   \seesect{Composite:}}%
\macrodef{arca}{arca}{({\sl absolute chord linespec}, ccw|cw, {\sl radius},
   {\sl modifiers}) }%
  {gen}%
  {arc with acute angle (obtuse if radius is negative), drawn in a [ ] block}%
\macrodef{ArcAngle}{ArcAngle}{({\sl position, position, position, radius,
  modifiers, label}) }%
  {gen}%
  {Arc angle symbol drawn ccw at arg2. Arg4 is the radius from arg2;
     arg5 contains line attributes, e.g., {\tt thick linethick/2 ->};
     arg6 is an optional label at mid-arc}%
\macrodef{arcd}{arcd}{({\sl center},
  {\sl radius},{\sl start degrees},{\sl end degrees}) }%
  {gen}%
  {Arc definition (see {\tt arcr}), angles in degrees
    \seesect{Positions:}}%
\macrodef{arcdimension\_}{arcdimension_}{({\sl arcspec}, {\sl offset},
    {\sl label}, D|H|W|{\sl blank width}, {\sl tic offset}, {\tt -> | <-})}%
  {gen}%
  {arcs with arrowheads for dimensioning an angle in a technical drawing,
    similar to {\tt dimension\_};
      Arg1 defines the attributes of an invisible arc: {\tt arc invis }arg1.\\
      Arg2 is the radial displacement (possibly negative) of the
      dimension arrows from the arc.\\
      Arg3: label, normally a number or number with unit symbol.\\
      Arg4: if arg3 is {\tt s\_box(\ldots)} or {\tt rs\_box(\ldots)} and
      arg4 is one of {\tt D,H,W} then arg4 means:\\
      {\tt D:} blank width is the diagonal length of arg3;\\
      {\tt H:} blank width is the height of arg3 + {\tt textoffset*2};\\
      {\tt W:} blank width is the width of arg3 + {\tt textoffset*2};\\
      otherwise arg4 is the absolute blank width.\\
      Arg5 is {\tt -> | <-} to designate a single arrowhead
      at the end or start of the reference arc; otherwise both arrowheads
      are drawn by default.}%
\macrodef{arcr}{arcr}{({\sl center},{\sl radius},{\sl start angle},{\sl
    end angle,modifiers,ht}) }%
  {gen}%
  {Arc definition. If arg5 contains {\tt <-} or {\tt ->} then a midpoint
    arrowhead of height equal to arg6 is added. Arg5 can contain modifiers
    (e.g. outlined "red"), for the arc and arrowhead.  Modifiers following
    the macro affect the arc only,
    e.g., {\tt arcr(A,r,0,pi\_/2,->) dotted ->}%
   \seesect{Positions:}}%
\macrodef{arcto}{arcto}{({\sl position 1}, {\sl position 2},
    {\sl radius}, [dashed|dotted])}%
  {gen}%
  {line toward position 1 with rounded corner toward position 2}%
\macrodef{arcwinding}{arcwinding}{({\sl
    winding diam, start degrees, end degrees, nturns, core centre rad,
    core width, {\tt "}core color{\tt "}})}%
  {cct}%
  {winding drawn on an arc. The complete spline is drawn, then parts of it
   are overwritten with the background color (default white).  Negative
   arg5 (default {\tt dimen\_} puts winding terminals at the outside.\\
   Example: {\tt W: arcwinding(1.2,-20,20,8, -1,0.8)}\\
   \seesect{Composite:}}%
\macrodef{array}{array}{({\sl variable, expr1, expr2, \ldots})}%
  {dpictools}%
  {$\;\;$  Populate a singly-subscripted array:
    {\tt {\sl var}[1]={\sl expr1;} {\sl var}[2]={\sl expr2;} \ldots}.}%
\macrodef{array2}{array2}{({\sl variable, expr1, expr2, \ldots})}%
  {dpictools}%
  {$\;\;$  Populate a doubly-subscripted array:
    {\tt {\sl var}[{\sl expr1},1]={\sl expr2;}
         {\sl var}[{\sl expr1},2]={\sl expr3;} \ldots}.}%
\macrodef{arraymax}{arraymax}{({\sl data array, n, index name, value})}%
  {dpictools}%
  {$\;\;$ Find the index in {\sl array[1:n]} of the first occurrence
   of the maximum array element value.  The value is assigned if arg4 is
   nonblank; example: 
   {\tt array(x,4,9,8,6); arraymax( x,4,i )}
    assigns 2 to {\sl i,} and {\tt arraymax( x,4,i,m )}
    assigns 2 to {\sl i} and 9 to {\sl m.}}%
\macrodef{arraymin}{arraymin}{({\sl data array, n, index name, value})}%
  {dpictools}%
  {$\;\;$ Find the index in {\sl array[1:n]} of the first occurrence
   of the minimum array element value.  The value is assigned if arg4 is
   nonblank; see {\tt arraymax}.}%
\macrodef{arrester}{arrester}{(\linespec, {\sl chars}[D[L|R]],
                                   {\sl body len}[:{\sl arrowhead ht}],
                                   {\sl body ht}[:{\sl arrowhead wid}],
                                   {\sl attributes} )}%
  {cct}%
{Arg2 {\sl chars:}\\
    {\tt G=} spark gap (default)\\
    {\tt g=} general (dots)\\
    {\tt E=} gas discharge\\
    {\tt S=} box enclosure\\
    {\tt C=} carbon block\\
    {\tt A=} electrolytic cell\\
    {\tt H=} horn gap\\
    {\tt P=} protective gap\\
    {\tt s=} sphere gap\\
    {\tt F=} film element\\
    {\tt M=} multigap\\
    {\sl Modifiers appended to arg2:}\\
    {\tt R=} right orientation\\
    {\tt L=} left orientation\\
    {\tt D=} for {\tt S, E} only, create a 3-terminal composite element
      with terminals {\sl A, B, G,} placed as a block since Arg1 now determines
      length and direction but not position.\\
    \seesect{Twoterminal:}}%
\macrodef{arrowline}{arrowline}{(\linespec)}%
  {cct}%
  {line (dotted, dashed permissible) with centred arrowhead
    \seesect{Twoterminal:}}%
\macrodef{assign3}{assign3}{({\sl name, name, name, arg4, arg5, arg6})}%
  {gen}%
  {Assigns \$1 = arg4 if \$1 is nonblank; similarly \$2 = arg5 and \$3 = arg6}%
\macrodef{AutoGate}{AutoGate}{\relax}%
  {log}%
  {Draw the tree for a gate as in the {\tt Autologix} macro.  No inputs
   or external connections are drawn.  The names of the internal gate
   inputs are stacked in {\tt `AutoInNames'}}%
\macrodef{Autologix}{Autologix}%
 {({\sl Boolean function sequence},%
    [N[oconnect]][L[eftinputs]][R][V][M][;offset={\sl value}])}%
  {log}%
  {Draw the Boolean expressions defined in function notation.
   The first argument is a semicolon (;)-separated sequence of
   Boolean function specifications using the functions
   {\tt And, Or, Not, Buffer, Xor, Nand, Nor, Nxor}
   with variables, e.g.,
   {\tt Autologix(And(Or(x1,\~{}x2),Or(\~{}x1,x2)));}.\\
   Each function specification is of the form\\
   {\tt {\sl function}({\sl arguments}) [@{\sl attributes}]}.
   \par
   Function outputs are aligned vertically but appending
   {\tt@}{\sl attributes} to a function can be used to place it; e.g.,
   {\tt Nand(\~{}A,B) @with .n at last [].s+(0,-2bp\_\_).}
   \par
   The function arguments are variable names or nested Boolean functions.
   Each unique variable {\sl var} causes an input point {\tt In}{\sl var}
   to be defined.  Preceding the variable by a {\tt \~{}} causes a NOT gate
   to be drawn at the input.
   The inputs are drawn in a row at the upper left by default.
   An {\tt L} in arg2 draws the inputs in a column at the left;
   {\tt R} reverses the order of the drawn inputs;
   {\tt V} scans the expression from right to left
   when listing inputs;
   {\tt M} draws the left-right mirror image of the diagram;
   and {\tt N} draws only the function tree without the input array.
   The inputs are labelled {\tt In1}, {In2}, \ldots and the function
   outputs are {\tt Out1}, {Out2}, \dots.
   Each variable {\sl var} corresponds also to one of the input array
   points with label {\tt In}{\sl var}.
   Setting {\tt offset=}{\sl value} displaces the
   drawn input list in order to disambiguate the input connections when {\tt L}
   is used.
   \par
   In the (possibly rare) case where one or more inputs of a normal function
   gate is to have a NOT-circle, an additional first argument of the function
   is inserted, of the form {\tt [{\sl charseq}]}, where {\sl charseq}
   is a string containing the characters {\tt P} for a normal input or
   {\tt N} for a negated input, the length of the string equal to the number
   of gate inputs.  Example:
   {\tt Autologix(Xor([PN],And(x,y),And(x,y)),LRV)}}%

\Letter{B}%
\macrodef{basename\_}{basename_}{({\sl string sequence, separator})}%
  {gen}%
  {Extract the rightmost name from a sequence of names separated by arg2
   (default dot ``.'')}%
\macrodef{battery}{battery}{(\linespec,{\sl n},R)}%
  {cct}%
  {n-cell battery: default 1 cell,
  R=reversed polarity\seesect{Twoterminal:}}%
\macrodef{b\_}{b_}{}%
  {gen}%
  {blue color value}%
\macrodef{b\_current}{b_current}{({\sl label}, {\sl pos}, In|Out, Start|End,
    {\sl frac})}%
  {cct}%
  {labelled branch-current arrow to {\sl frac} between branch end and body
    \seesect{Branchcurrent:}}%
\macrodef{beginshade}{beginshade}{({\sl gray value})}%
  {gen}%
  {begin gray shading, see {\tt shade}%
   e.g., {\tt beginshade(.5);} {\sl closed line specs}; {\tt endshade}}%
\macrodef{bell}{bell}{( U|D|L|R|{\sl degrees}, {\sl size})}%
  {cct}%
  {bell, {\sl In1} to {\sl In3} defined
   \seesect{Composite:}}%
\macrodef{below\_}{below_}{}%
  {gen}%
  {string position relative to current direction}%
\macrodef{Between\_}{Between_}{({\sl Pos1, Pos2,distance,}[R])}%
  {gen}%
  {Position {\sl distance} from {\sl Pos1} toward {\sl Pos2}.  If
   the fourth arg is {\tt R} then from {\sl Pos2} toward {\sl Pos1}.}%
\macrodef{binary\_}{binary_}{($n$, [$m$])}%
  {gen}%
  {binary representation of $n,$ left padded to $m$ digits if the second
   argument is nonblank}%
\macrodef{bisect}{bisect}{%
  ({\sl function name, left bound, right bound, tolerance, variable}))}%
  {dpictools}%
  {$\;\;$ Solve $\hbox{\sl function}(x) = 0$ by the method of 
   bisection.
   Like {\tt findroot} but uses recursion and is without a {\tt[]} box.
   The calculated value is assigned to the variable named in the
   last argument (\SR{Libraries:}). Example:\\
   {\tt define parabola \{ \$2 = (\$1)\char94{}2 - 1 \};\\
   bisect( parabola, 0, 2, 1e-8, x )}. }%
\macrodef{bi\_trans}{bi_trans}{(\linespec,L|R,{\sl chars},E)}%
  {cct}%
  { bipolar transistor, core left or right; chars:\\
   {\tt BU}: bulk line\\
   {\tt B}: base line and label\\
   {\tt S}: Schottky base hooks\\
   {\tt uEn|dEn}: emitters E0 to En\\
   {\tt uE|dE}: single emitter\\
   {\tt Cn|uCn|dCn}: collectors C0 to Cn; {\tt u} or {\tt d} add an arrow\\
   {\tt C}: single collector; {\tt u} or {\tt d} add an arrow\\
   {\tt G}: gate line and location\\
   {\tt H}: gate line;\\
   {\tt L}: L-gate line and location\\
   {\tt [d]D}: named parallel diode\\
   {\tt d}: dotted connection\\
   {\tt [u]T}: thyristor trigger line\\
   arg 4 = {\tt E}: envelope
    \seesect{Semiconductors:}}%
\macrodef{bi\_tr}{bi_tr}{(\linespec,L|R,P,E)}%
  {cct}%
  {left or right, N- or P-type bipolar transistor, without or with envelope 
    \seesect{Semiconductors:}}%
\macrodef{boxcoord}{boxcoord}{({\sl planar obj}, {\sl x fraction},
    {\sl y fraction})}%
  {gen}%
  {internal point in a planar object}%
\macrodef{boxdim}{boxdim}{({\sl name},h|w|d|v,{\sl default})}%
  {gen}%
  {Evaluate, e.g.\ {\sl name}{\tt \_w} if defined, else {\sl default\/}
   if given, else 0. {\tt v} gives sum of {\tt d} and {\tt h} values
     \seesect{Interaction:}}%
\macrodef{BOX\_gate}{BOX_gate}{({\sl inputs, output, swid, sht, label,
    attributes })}%
  {log}%
  {output=[{\tt P|N}], inputs=[{\tt P|N}]$\ldots$, sizes swid and sht
  in {\tt L\_unit}s (default {\tt AND\_wd} = 7)
    \seesect{Logicgates:}}%
\macrodef{bp\_\_}{bp__}{}%
  {gen}%
  {big-point-size factor, in scaled inches, ({\tt *scale/72})}%
\macrodef{bswitch}{bswitch}{(\linespec, [L|R],chars)}%
  {cct}%
  {pushbutton switch R=right orientation (default L=left);
     chars: O= normally open, C=normally closed }%
\macrodef{BUFFER\_gate}{BUFFER_gate}{(\linespec, [N|B],
  {\sl wid, ht,} [N|P]\char42, [N|P]\char42, [N|P]\char42,
    {\sl attributes})}%
  {log}%
  {basic buffer, dfault 1 input or as a 2-terminal element,\\
    arg2: {\tt N}: negated input, {\tt B}: box gate;\\
    arg 5: normal ({\tt P}) or negated {\tt N}) inputs labeled In1 
    \seesect{Logicgates:}}%
\macrodef{BUFFER\_gen}{BUFFER_gen}{({\sl chars,wd,ht},[N|P]*,[N|P]*,[N|P]*,
    {\sl attributes})}%
  {log}%
  {general buffer, {\sl chars:}\\
            {\tt T}: triangle,\\
            {\tt [N]O}: output location {\tt Out}
            ({\tt NO} draws circle {\tt N\_Out});\\
            {\tt [N]I, [N]N, [N]S, [N]NE, [N]SE} input locations;\\
            {\tt C}: centre location.\\
            Args 4-6 allow alternative
            definitions of respective {\tt In, NE,}
            and {\tt SE} argument sequences }%
\macrodef{BUF\_ht}{BUF_ht}{}%
  {log}%
  {basic buffer gate height in {\tt L\_unit}s, default 4}%
\macrodef{BUF\_wd}{BUF_wd}{}%
  {log}%
  {basic buffer gate width in {\tt L\_unit}s, default 3.5}%
\macrodef{buzzer}{buzzer}{( U|D|L|R|{\sl degrees, size,}[C])}%
  {cct}%
  {buzzer, {\sl In1} to {\sl In3} defined, C=curved
   \seesect{Composite:}}%

\Letter{C}%
\macrodef{cangle}{cangle}{({\sl Start, End},[d])}%
  {gen}%
  {Angle in radians of the sector at arg2 with arm ends given
   by arg1 and arg3 (degrees if arg4=d).}%
\macrodef{capacitor}{capacitor}{(\linespec,{\sl chars},R,
    {\sl height}, {\sl wid})}%
  {cct}%
  {capacitor, {\sl chars}:\\
    {\tt F} or blank: flat plate\\
    {\tt dF} flat plate with hatched fill\\
    {\tt C} curved-plate\\
    {\tt dC} curved-plate with variability arrowhead\\
    {\tt CP} constant phase element\\
    {\tt E} polarized boxed plates\\
    {\tt K} filled boxed plates\\
    {\tt M} unfilled boxes\\
    {\tt N} one rectangular plate\\
    {\tt P} alternate polarized\\
    {\tt +} adds a polarity sign\\
    {\tt +L} polarity sign to the left of drawing direction\\
    arg3:  {\tt R=}reversed polarity\\
    arg4: height (defaults {\tt F:} {\tt dimen\_}$/3$,
      {\tt C,P:} {\tt dimen\_}$/4$,
      {\tt E,K:} {\tt dimen\_}$/5$)\\
    arg5: wid (defaults {\tt F:} {\sl height}*0.3,
      {\tt C,P:} {\sl height}*0.4,
      {\tt CP:} {\sl height}*0.8,
      {\tt E,K:} {\sl height})
    \seesect{Twoterminal:}}%
\macrodef{case}{case}{({\sl i, alt1, alt2, \ldots})}%
  {dpictools}%
  {$\;\;$ Case statement for dpic; execute alternative {\sl i.}
   Example: {\tt case( 2, x=5, x=10, x=15 )} sets {\tt x} to 10.
   Note: this is a macro so {\tt \${}n} refers to the {\sl n}-th
	 argument of {\tt case}.}%
\macrodef{cbreaker}{cbreaker}{(\linespec, L|R, D|Th|TS, body name)}%
  {cct}%
  {circuit breaker to left or right, {\tt D}: with dots; {\tt Th}: thermal;
   {\tt TS}: squared thermal; default body bounding box name is
     {\sl Br}\seesect{Twoterminal:}}%
\macrodef{ccoax}{ccoax}{(at {\sl location}, M|F, {\sl diameter, attributes})}%
  {cct}%
  {coax connector, {\tt M}: male, {\tt F}: female
    \seesect{Composite:}}%
\macrodef{cct\_init}{cct_init}{}%
  {cct}%
  {initialize circuit-diagram environment (reads {\tt libcct.m4})}%
\macrodef{centerline\_}{centerline_}{({\sl linespec, thickness{\tt|}color,
   minimum long dash len, short dash len, gap len}}%
  {gen}%
  {Technical drawing centerline}%
\macrodef{c\_fet}{c_fet}{(\linespec,R,P)}%
  {cct}%
  {left or right, plain or negated pin simplified MOSFET}%
\macrodef{Cintersect}{Cintersect}{({\sl Pos1, Pos2, rad1, rad2,} [R])}%
  {gen}%
  {Upper (lower if arg5={\tt R}) intersection of circles at
    {\sl Pos1} and {\sl Pos2}, radius {\sl rad1} and {\sl rad2}}
\macrodef{clabel}{clabel}{( {\sl label}, {\sl label}, {\sl label},
    {\sl relative position}, {\sl block name})}%
  {cct}%
  {Triple label along the drawing axis of the body of an element in the
    current direction \seesect{Labels:}.  Labels are placed at the
    beginning, centre, and end of the last {\tt []} block (or a {\tt
    []} block named or enumerated in arg5). Each label is treated as
    math by default, but is copied literally if it is in double quotes
    or sprintf.  {\sl Arg4} can be {\tt above,} {\tt below,} {\tt left,}
    or {\tt right} to supplement the default relative position.}%
\macrodef{cm\_\_}{cm__}{}%
  {gen}%
  {absolute centimetres}%
\macrodef{cmyktorgb}{cmyktorgb}{({\sl c, m, y, k, r, g, b})}%
  {dpictools}%
  {$\;\;$ cmyk values in percent, i.e., 0 to 100, to rgb.}%
\macrodef{consource}{consource}{(\linespec, V|I|tv|v|ti|i|P, R,
    {\sl attributes})}%
  {cct}%
  {controlled source or sensor with alternate forms;
   {\tt V}: voltage;
   {\tt I}: current;
   {\tt v}: voltage type 2;
   {\tt tv}: voltage type 3;
   {\tt i}: current type 2;
   {\tt ti}: current type 3;
   {\tt P}: proximity sensor;
   {\tt R}: reversed polarity.
  Body internal locations N, S, E, W, and C are defined.
  Arg 4 can be used to modify the body or to add internal symbols, e.g.\\
    {\tt consource(,{,},fill\_(0.9); "S" at C)}\seesect{Twoterminal:}}%
\macrodef{ColoredV}{ColoredV}{%
   (box|circle|ellipse,({\sl r,g,b})|(({\sl colorseq}))[:{\sl nlines}],%
     {\sl attributes})}%
  {gen}%
  {box (default), circle, or ellipse in a {\tt []} block.
   If arg2 is blank
   then all formatting is in arg3; if parenthesized r,g,b, the object
   is shaded top to bottom white to the specified rgb color; if a
   double-parenthesized {\sl colorseq} then the {\sl colorseq}
   defines the internal
   shading top to bottom.  A {\sl colorseq} is of the form
   {\sl 0,r0,g0,b0,\\
    frac1,r1,g1,b1,\\
    frac2,r2,g2,b2,\\
   \ldots\\
    1,rn,gn,bn}\\
   with $0 < \hbox{\sl frac1} < \hbox{\sl frac2} \ldots 1$.
   The number of {\sl colorseq} lines can be specified with the colon
   (default {\tt height/(line thickness)*2)}.
   Examples: {\tt ColoredV(circle,(1,0,0));
   ColoredV(ellipse,(1,0.04,1),wid 0.75 ht 1 \textbackslash\\
    $\;$ outlined "magenta" "Goodbye");
   ColoredV(box,((0,1,1,0, 1,0,0,1)):50, \\
    $\;$ outlined "blue" rad 0.1).} }%
\macrodef{contact}{contact}{({\sl chars})}%
  {cct}%
  {single-pole contact:
   {\tt O}:  normally open\\
   {\tt C}: normally closed (default)\\
   {\tt I}: open circle contacts\\
   {\tt P}: three position\\
   {\tt R}: right orientation\\
   {\tt T}: T contacts\\
   {\tt U}: U contacts
   \seesect{Composite:}}%
\macrodef{contacts}{contacts}{({\sl count, chars})}%
  {cct}%
  {multiple ganged single-pole contacts:
   {\tt P}: three position\\
   {\tt O}: normally open\\
   {\tt C}: normally closed\\
   {\tt D}: dashed ganging line over contact armatures
   {\tt I}: open circle contacts\\
   {\tt R}: right orientation\\
   {\tt T}: T contacts\\
   {\tt U}: U contact lines parallel to drawing direction
   \seesect{Composite:}}%
\macrodef{contline}{contline}{({\sl line})}%
  {gen}%
  {evaluates to {\tt continue}
    if processor is {\bf dpic}, otherwise to first arg (default {\tt line})}%
\macrodef{copy3}{copy3}{({\sl vector1,vector2})}%
  {dpictools}%
  {$\;\;$ Copy vector1 into vector named by arg2.}%
\macrodef{copythru}{copythru}{({\sl dpic macro name,} "{\sl file name}")}%
  {dpictools}%
  {$\;\;$ Implements the gpic {\tt copy {\sl filename} thru {\sl macro-name}}
   for file data separated by commas, spaces, or tabs.}%
\macrodef{corner}{corner}{({\sl line thickness,attributes,turn radians})}%
  {gen}%
  { Mitre (default filled square) drawn at end of last line or at a
    given position.
    arg1 default: current line thickness;
    arg2: e.g. {\tt outlined} {\sl string}; if arg2 starts with
    {\tt at} {\sl position} then a manhattan (right-left-up-down) corner
    is drawn;
    arg3= radians (turn angle, +ve is ccw, default $\pi/2$).
    The corner is enclosed in braces
    in order to leave {\tt Here} unchanged unless arg2 begins with {\tt at}%
    \seesect{Corners:}}%
\macrodef{Cos}{Cos}{({\sl integer})}%
  {gen}%
  {cosine function, {\sl integer\/} degrees}%
\macrodef{cosd}{cosd}{({\sl arg})}%
  {gen}%
  {cosine of an expression in degrees}%
\macrodef{Cosine}{Cosine}{( {\sl amplitude}, {\sl freq}, {\sl time},
    {\sl phase} )}%
  {gen}%
  {function $a\times\cos(\omega t + \phi)$ }%
\macrodef{cross3}{cross3}{({\sl vec1, vec2, vec3})}%
  {dpictools}%
  {$\;\;$ The 3-vector cross product
    $\hbox{\sl vec3} = \hbox{\sl vec1} \times \hbox{\sl vec2}$.}%
\macrodef{cross3D}{cross3D}{({\sl x1,y1,z1,x2,y2,z2})}%
  {3D}%
  {cross product of two triples}%
\macrodef{cross}{cross}{(at {\sl location, size}|{\sl keys})}%
  {gen}%
  {Plots a small cross.  The possible key-value pairs are:
    {\tt size={\sl expr};},
    {\tt line={\sl attributes};} }%
\macrodef{crossover}{crossover}{(\linespec, [L|R][:{\sl line attributes}],
  {\sl Linename1, Linename2,} $\ldots$)}%
  {cct}%
  {line jumping left or right over ordered named
   lines\seesect{Semiconductors:}}%
\macrodef{crosswd\_}{crosswd_}{}%
  {gen}%
  {cross dimension}%
\macrodef{csdim\_}{csdim_}{}%
  {cct}%
  {controlled-source width}%

\Letter{D}%
\macrodef{dabove}{dabove}{(at {\sl location})}%
  {darrow}%
  {above (displaced dlinewid/2)}%
\macrodef{dac}{dac}{({\sl width,height,nIn,nN,nOut,nS})}%
  {cct}%
  {DAC with defined width, height, and number of inputs {\tt In$i$},
    top terminals {\tt N$i$}, ouputs {\tt Out$i$},
    and bottom terminals~{\tt S$i$} \seesect{Logicgates:}}%
\macrodef{Darc}{Darc}{({\sl center position},
  {\sl radius}, {\sl start radians}, {\sl end radians},
  {\sl parameters})}%
  {darrow}%
  {Wrapper for {\tt darc}.
   CCW arc in {\tt dline} style, with closed ends or (dpic only) arrowheads.
  Semicolon-separated {\sl parameters}:\\
  {\tt thick=}{\sl value};\\
  {\tt wid=}{\sl value};\\
  {\tt ends=} {\sl x}{\tt -},
  {\tt -}{\sl x}, {\sl x}{\tt -}{\sl x}, {\tt ->}, {\sl x}{\tt ->},
  {\tt <-}, {\tt <-}{\sl x}, {\tt <->},
  where {\sl x} is {\tt |} or (half-thickness line) {\tt !}.}%
\macrodef{darc}{darc}{({\sl center position},
  {\sl radius}, {\sl start radians}, {\sl end radians}, {\sl dline thickness},
  {\sl arrowhead wid}, {\sl arrowhead ht},
  {\sl end symbols}, {\sl outline attributes}, {\sl inner attributes})}%
  {darrow}%
  {See also {\tt Darc}.
   CCW arc in {\tt dline} style, with closed ends or (dpic only) arrowheads.
  Permissible {\sl end symbols}:
  {\sl x}{\tt -},
  {\tt -}{\sl x}, {\sl x}{\tt -}{\sl x}, {\tt ->}, {\sl x}{\tt ->},
  {\tt <-}, {\tt <-}{\sl x}, {\tt <->}
  where {\sl x} is {\tt |} or (half-thickness line) {\tt !}.
  An inner arc is drawn overlaying the outer arc.
  Example: {\tt darc(,{,},{,},{,},{,}outlined "red",outlined "yellow")}.}%
\macrodef{Darlington}{Darlington}{(L|R,{\sl chars})}%
  {cct}%
  {Composite Darlington pair Q1 and Q2 with internal locations E, B, C;
   Characters in {\sl arg2:}\\
   E= envelope\\
   P= P-type\\
   B1= internal base lead\\
   D= damper diode\\
   R1= Q1 bias resistor; E1= ebox\\
   R2= Q2 bias resistor; E2= ebox (require R1 or E1)\\
   Z= zener bias diode 
    \seesect{Semiconductors:}}%
\macrodef{darrow}{darrow}{(\linespec,
  t, t, {\sl width}, {\sl arrowhd wd}, {\sl arrowhd ht}, {\sl parameters}, 
    {\sl color attributes})}%
  {darrow}%
  {See also {\tt Darrow}.
   Double arrow, truncated at beginning (arg2={\tt t}) or
    end (arg3={\tt t}), specified sizes,
    with arrowhead and optional closed stem. The parameters (arg7) are
    {\tt {\sl x}-} or {\tt ->} or {\tt {\sl x}->} or {\tt <-} or
    {\tt <-{\sl x}}
    or {\tt <->} where {\sl x} is {\tt |} or {\tt !}.
    The {\tt !-} or {\tt -!} parameters close
    the stem with half-thickness lines to simplify butting to other objects.
    The color attributes are, e.g.,
    {\tt outlined "{\sl color}" shaded "{\sl color}"}.
    Example:
    {\tt linethick=5; darrow(down\_\ 2,{,},0.5,0.75,0.75,|,outlined "red")}. }%
\macrodef{Darrow}{Darrow}{(\linespec, {\sl parameters})}%
  {darrow}%
  {Wrapper for {\tt darrow}.
  Semicolon-separated {\sl parameters}:\\
    {\tt S;}, {\tt E;} truncate at start or end by dline thickness/2\\
    {\tt thick=}{\sl val};   (total thicknes, ie width)\\
    {\tt wid=}{\sl val};     (arrowhead width)\\
    {\tt ht=}{\sl val};      (arrowhead height)\\
    {\tt ends=}
      {\sl x}{\tt -}{\sl x} or
      {\tt -}{\sl x} or
      {\sl x}{\tt -} where {\sl x} is {\tt !} (half-width line)
       or {\tt |} (full-width line).\\
    Examples:
    {\tt define(`dfillcolor',`1,0.85,0') linethick=5;
     rgbdraw(1,0,0,Darrow(down\_\ 2,thick=0.5; wid=0.75; ht=0.75; ends=|->))},
     which is equivalent to
    {\tt Darrow(down\_\ 2,thick=0.5; wid=0.75; ht=0.75; \
      ends=|->; outline="red")}.  }%
\macrodef{darrow\_init}{darrow_init}{}%
  {darrow}%
  {Initialize darrow drawing parameters (reads library file {\tt darrow.m4})}%
\macrodef{dashline}{dashline}{(\linespec,{\sl thickness}|{\sl color}|<->|->|<-,
                                  {\sl dash len, gap len},G)}%
  {gen}%
  {Dashed line with dash at end ({\tt G} ends with gap). Dashes are
   adjusted to fit with given gap length. Dpic only.}%
\macrodef{dbelow}{dbelow}{(at {\sl location})}%
  {darrow}%
  {below (displaced dlinewid/2)}%
\macrodef{dcosine3D}{dcosine3D}{({\sl i,x,y,z})}%
  {3D}%
  {extract i-th entry of triple x,y,z}%
\macrodef{DCsymbol}{DCsymbol}{(at {\sl position, len, ht,}%
  U|D|L|R|{\sl degrees}) }%
  {cct}%
  {A DC symbol (a dashed line below a solid line).
   The current drawing direction is default, otherwise Up, Down,
   Left, Right, or at {\sl degrees} slant; e.g., 
   {\tt source(up\_ dimen\_); $\lbrace$ DCsymbol(at last [],{},{},R) $\rbrace$}
   \seesect{Twoterminal:} }%
\macrodef{DefineCMYKColor}{DefineCMYKColor}{({\sl color-name, c, m, y, k})}%
  {dpictools}%
  {$\;\;$ Like {\tt DefineRGBColor} but takes arguments in percent, i.e.,
    the range $[0,100].$ Define dpic macro {\sl colorname}
    according to the postprocessor specified by dpic command-line option.
    The macro evaluates to a string.}%
\macrodef{DefineHSVColor}{DefineHSVColor}{({\sl color-name, h, s, v})}%
  {dpictools}%
  {$\;\;$ Like {\tt DefineRGBColor} but takes argument {\sl h} in the
    range $[0,360],$ {\sl s} in $[0,1],$ and {\sl v} in $[0,1].$
    Define dpic macro {\sl colorname}
    according to the postprocessor specified by dpic command-line option.
    The macro evaluates to a string.}%
\macrodef{DefineRGBColor}{DefineRGBColor}{({\sl color-name, r, g, b})}%
  {dpictools}%
  {$\;\;$ Arguments are in the range 0 to 1. Define dpic macro {\sl colorname}
    according to the postprocessor specified by dpic command-line option.
    The macro evaluates to a string.}%
\macrodef{definergbcolor}{definergbcolor}{({\sl color-name, r, g, b})}%
  {gen}%
  {Arguments are in the range 0 to 1. Define color name
    according to the postprocessor.  Similar to dpictools {\tt DefineRGBColor}
    but the color name is an m4 macro, not a string.}%
\macrodef{delay}{delay}{(\linespec,{\sl size},{\sl attributes})}%
  {cct}%
  {delay element\seesect{Twoterminal:}}%
\macrodef{delay\_rad\_}{delay_rad_}{}%
  {cct}%
  {delay radius}%
\macrodef{deleminit\_}{deleminit_}{}%
  {darrow}%
  {sets drawing direction for dlines}%
\macrodef{Deltasymbol}{Deltasymbol}{(at {\sl position, keys,}
    U|D|L|R|{\sl degrees, attributes}) (default {\tt U} for up)}%
  {cct}%
  {Delta symbol for power-system and other diagrams.
   {\sl keys:} {\tt size={\sl expression;}}
    {\tt type=C|O} (default {\tt C} for closed;
      {\tt O} draws an ``open'' symbol).\\
     Arg4 contains attributes of the drawn line object }%
\macrodef{Demux}{Demux}{({\sl n},{\sl label},
  {\tt [L][B|H|X][N[{\sl n}]|S[{\sl n}]][[N]OE],
   {\sl wid},{\sl ht},{\sl attributes}})}%
  {log}%
  {binary demultiplexer, $n$ inputs\\
    Arg5 is of the form {\sl expr}{\tt [:{\sl expr}]}, i.e. right (output)-side
     height optionally followed by left (input)-side height;\\
    {\tt L} reverses input pin numbers\\
    {\tt B} displays binary pin numbers\\
    {\tt H} displays hexadecimal pin numbers\\
    {\tt X} do not print pin numbers\\
    {\tt N[{\sl n}]} puts Sel or Sel$0$ .. Sel$n$ at the top
    (i.e., to the left of the drawing direction)\\
    {\tt S[{\sl n}]} puts the Sel inputs at the bottom (default)
    {\tt OE} ({\tt N=}negated) {\tt OE} pin
    \seesect{Logicgates:}}%
\macrodef{dend}{dend}{(at {\sl location},
  {\sl line thickness}{\tt |}{\sl attributes})}%
  {darrow}%
  {Close (or start) double line (Note specifying {\tt dends=} for {\tt Dline}
   is a similar function.  Arg2 is dline thickness or atributes:\\
   {\tt thick={\sl expression};} (dline thickness in drawing units)\\
   {\tt outline=({\sl r,g,b})|"{\sl color}";}}%
\macrodef{d\_fet}{d_fet}{(\linespec,R,P,E|S)}%
  {cct}%
  {left or right, N or P depletion MOSFET, envelope or simplified
    \seesect{Semiconductors:}}%
\macrodef{dfillcolor}{dfillcolor}{}%
  {darrow}%
  {dline fill color (default white)}%
\macrodef{diff3}{diff3}{({\sl vec1, vec2, vec3})}%
  {dpictools}%
  {$\;\;$ The 3-vector subtraction
    $\hbox{\sl vec3} = \hbox{\sl vec1} - \hbox{\sl vec2}$.}%
\macrodef{dfitcurve}{dfitcurve}{({\sl Name, n, linetype, m})}%
  {dpictools}%
  {$\;\;$ Draw a spline through {\sl Name}{\tt [m],} \ldots {\sl Name}{\tt [n]}
   with attribute {\sl linetype} {\tt dotted,} for example.
   The calculated control points {\sl P[i]} satisfy approximately:
   {\sl P[0] = V[0];} {\sl P[i-1]/8 + P[i]*3/4 + P[i+1]/8 = V[i];}
   {\sl P[n] = V[n].}  See m4 macro {\tt fitcurve.}}%
\macrodef{dfitpoints}{dfitpoints}{({\sl V,n,m,P,mp})}%
  {dpictools}%
  {$\;\;$ Compute the control locations {\tt P[mP], P[mP+1]...} for
  the spline passing throught points {\tt V[m]...V[n].}  Used by
  macro {\tt dfitcurve}.}%
\macrodef{diff3D}{diff3D}{({\sl x1,y1,z1,x2,y2,z2})}%
  {3D}%
  {difference of two triples}%
\macrodef{diff\_}{diff_}{({\sl a},{\sl b})}%
  {gen}%
  {difference function}%
\macrodef{dimen\_}{dimen_}{}%
  {cct}%
  {size parameter for scaling circuit element bodies \seesect{Circuitscaling:}}%
\macrodef{dimension\_}{dimension_}{(\linespec, {\sl offset}, {\sl label},
    D|H|W|{\sl blank width}, {\sl tic offset}, {\tt <- | ->})}%
  {gen}%
  {macro for dimensioning technical drawings;
      Arg1 defines the attributes
      of an invisible line: {\tt line invis }arg1.\\
      Arg2 is the sideways displacement (possibly negative) of the
      dimension arrows from the line.\\
      Arg3: label, normally a number or number with unit symbol but
        if arg3 begins with {\tt [} then it is copied verbatim.\\
      Arg4: if arg3 is {\tt s\_box(\ldots)} or {\tt rs\_box(\ldots)} and
      arg4 is one of {\tt D,H,W} then arg4 means:\\
      {\tt D:} blank width is the diagonal length of arg3;\\
      {\tt H:} blank width is the height of arg3 + {\tt textoffset*2};\\
      {\tt W:} blank width is the width of arg3 + {\tt textoffset*2};\\
      otherwise arg4 is the absolute blank width.\\
      Arg5 is {\tt -> | <-} to designate a single arrowhead
      at the end or start of the reference line; otherwise both arrowheads
      are drawn by default.}%
\macrodef{diode}{diode}{(\linespec,
B|b|CR|D|G|L|LE[R]|P[R]|S|Sh|SI|T|U|V|v|w|Z|z|{\sl chars,}
[R][E])}%
  {cct}%
  {diode:
   {\tt B}: bi-directional\\
   {\tt b}: bi-directional with outlined zener crossbar\\
   {\tt CR}: current regulator\\
   {\tt D}: diac\\
   {\tt G}: Gunn\\
   {\tt L}: open form with centre line\\
   {\tt LE[R]}: LED [right]\\
   {\tt P[R]}: photodiode [right]\\
   {\tt S}: Schottky\\
   {\tt Sh}: Shockley\\
   {\tt SI}: SIDAC (see \MR{SiDAC}{sidac})\\
   {\tt T}: tunnel\\
   {\tt U}: limiting\\
   {\tt V}: varicap\\
   {\tt v}: varicap (curved plate)\\
   {\tt w}: varicap (reversed polarity)\\
   {\tt Z}: zener\\
   {\tt z}: zener with angled centre bar\\
   appending {\tt K} to arg 2 draws open arrowheads;
   arg 3: {\tt R}: reversed polarity, {\tt E}: enclosure \seesect{Twoterminal:}}%
%\macrodef{DIP}{DIP}{({\sl pin count, attributes})}%
%  {log}%
%  {Dual in-line package diagram. Default pin count = 8.
%   Arg2 ({\sl attributes})= semicolon-separated list of optional terms:
%   {\tt bodywid=}{\sl expr} (default 0.25$\,$in${} {}$5{\tt *L\_unit}),
%   {\tt bodylen=}{\sl expr} (default {\sl pin count} $\times$ {\sl pin pitch}),
%   {\tt pinpitch=}{\sl expr} (default 0.1),
%   {\tt pinwid=}{\sl expr} (default 0.06),
%   {\tt pinlen=}{\sl expr} (default 0.05),
%   {\tt direct=U|D|L|R} (default {\tt U} for up),
%   {\tt type=I|Q} (default {\tt I}; Q=pins of alternating length)
%   \seesect{Logicgates:}}%
\macrodef{dir\_}{dir_}{}%
  {darrow}%
  {used for temporary storage of direction by darrow macros}%
\macrodef{distance}{distance_}{({\sl Position 1}, {\sl Position2})}%
  {gen}%
  {distance between named positions}%
\macrodef{distance}{distance}{({\sl position}, {\sl position})}%
  {gen}%
  {distance between positions}%
\macrodef{dlabel}{dlabel}{({\sl long},{\sl lat},{\sl label},{\sl
     label},{\sl label},{\sl chars})}%
  {cct}%
  {general triple label; {\sl chars:}
    $X$ displacement {\tt {\sl long, lat}} with respect to the drawing
      direction is from the centre of the last
      line rather than the centre of the last {\tt [ ]};
    L,R,A,B align labels ljust, rjust, above,
      or below (absolute) respectively  \seesect{Labels:}}%
\macrodef{dleft}{dleft}{({\tt at} {\sl position}, {\sl line thickness},
      {\sl attributes})}%
  {darrow}%
  {Double line left turn 90 degrees.  Attributes can be
    {\tt outline=({\sl r, g, b})|"{\sl color}";}
    {\tt innershade=({\sl r, g, b})|"{\sl color}";}
    where rgb values in parentheses or a defined color is specified.}%
\macrodef{Dline}{Dline}{(\linespec, {\sl parameters})}%
  {darrow}%
  {Wrapper for {\tt dline}.
  The semicolon-separated {\sl parameters} are:\\
    {\tt S;}, {\tt E;} truncate at start or end by dline thickness/2;\\
    {\tt thick={\sl val};}   (total thicknes, ie width);\\
    {\tt outline={\sl color};} (e.g., {\tt "red"} or {\tt (1,0,0)}),\\
    {\tt innershade={\sl color};} (e.g., {\tt (0,1,1)} or {\tt "cyan"}),\\
    {\tt name={\sl Name};},\\
    {\tt ends=}%
      {\sl x}{\tt -}{\sl x} or
      {\tt -}{\sl x} or
      {\sl x}{\tt -} where {\sl x} is {\tt !} (half-width line)
       or {\tt |;} (full-width line).}%
\macrodef{dline}{dline}{(\linespec,t,t,{\sl width},{\sl parameters})}%
  {darrow}%
  {See also {\tt Dline}.
   Double line, truncated by half width at either end, closed
    at either or both ends.
   {\sl parameters=}
      {\sl x}{\tt -}{\sl x} or
      {\tt -}{\sl x} or
      {\sl x}{\tt -} where {\sl x} is {\tt !} (half-width line)
       or {\tt |} (full-width line).}%
\macrodef{dlinewid}{dlinewid}{}%
  {darrow}%
  {width of double lines}%
\macrodef{dljust}{dljust}{(at {\sl location})}%
  {darrow}%
  {ljust (displaced dlinewid/2)}%
\macrodef{dna\_}{dna_}{}%
  {cct}%
  {internal character sequence that specifies which subcomponents are drawn}%
\macrodef{dn\_}{dnx}{}%
  {gen}%
  {down with respect to current direction}%
%\macrodef{dnm\_}{dnm_}{}%
%  {cct}%
%  {similar to dna\_}%
\macrodef{dot3}{dot3}{({\sl vec1, vec2})}%
  {dpictools}%
  {$\;\;$ Expands to the dot (scalar) product of the two 3-vector arguments:
   $(\${}1[1]\cdot\${}2[1] + \${}1[2]\cdot\${}2[2] + \${}1[3]\cdot\${}2[3])$.}%
\macrodef{dot3D}{dot3D}{({\sl x1,y1,z1,x2,y2,z2})}%
  {3D}%
  {dot product of two triples}%
\macrodef{dot}{dot}{(at {\sl location},{\sl radius}|{\sl keys},{\sl fill})}%
  {gen}%
  {Filled circle (third arg= gray value: 0=black, 1=white). The possible
   key-value pairs are:
    {\tt rad={\sl expr};} and
    {\tt circle={\sl attributes};} }%
\macrodef{dotrad\_}{dotrad_}{}%
  {gen}%
  {dot radius}%
\macrodef{down\_}{down_}{}%
  {gen}%
  {sets current direction to down \seesect{Placing:}}%
\macrodef{dpquicksort}{dpquicksort}{({\sl array name, lo, hi, ix})}%
  {dpictools}%
  {$\;\;$ Given array {\sl a[lo:hi]} and index array {\sl ix[lo:hi] =
    lo, lo+1, lo+2,\ldots hi}, sort {\sl a[lo:hi]} and do identical exchanges
    on {\sl ix}.}%
\macrodef{dprot}{dprot}{({\sl radians, x, y})}%
  {dpictools}%
  {$\;\;$ Evaluates to a rotated pair (see m4 {\tt rot\_}).}%
\macrodef{dprtext}{dprtext}{({\sl degrees, text})}%
  {dpictools}%
  {$\;\;$ Rotated PStricks or pgf text in a {\tt []} box.}%
\macrodef{dright}{dright}{({\tt at} {\sl position}, {\sl line thickness},
      {\sl attributes})}%
  {darrow}%
  {Double line right turn 90 degrees.  Attributes can be\\
    {\tt outline=({\sl r, g, b})|"{\sl color}";}\\
    {\tt innershade=({\sl r, g, b})|"{\sl color}";}\\
    where rgb values in parentheses or a defined color is specified.}%
\macrodef{drjust}{drjust}{(at {\sl location})}%
  {darrow}%
  {rjust (displaced dlinewid/2)}%
\macrodef{dswitch}{dswitch}{(\linespec, L|R, W[ud]B {\sl chars},
     {\sl attributes})}%
  {cct}%
  {
                                 Comprehensive IEEE-IEC single-pole switch:
                                 arg2={\tt R}: orient to the right of
                                     drawing dir\\
                                 arg4 is a key-value sequence for the body of
                                 {\tt GC} and {\tt GX} options:
                                   {\tt GC} keys: {\tt diam, circle;}%
                                   {\tt GX} keys: {\tt lgth, wdth, box, text}.
\par
                                 arg 3:
                                   blank means {\tt WB} by default\\
                                   {\tt B}: contact blade open\\
                                   {\tt Bc}: contact blade closed\\
                                   {\tt Bm}: mirror blade\\
                                   {\tt Bo}: contact blade more widely open\\
                                   {\tt dB}: contact blade to the right of
                                     direction\\
                                   {\tt Cb}: circuit breaker function 
                                     (IEC S00219)\\
                                   {\tt Co}: contactor function (IEC S00218)\\
                                   {\tt C}: external operating mechanism\\
                                   {\tt D}: circle at contact and hinge
                                      ({\tt dD} = hinge only,
                                       {\tt uD}: contact only)\\
                                   {\tt DI}: Disconnector, isolator
                                     (IEC S00288)\\
                                   {\tt E}: emergency button\\
                                   {\tt EL}: early close (or late open)\\
                                   {\tt LE}: late close (or early open)\\
                                   {\tt F}: fused\\
                                   {\tt GC}: disk control mechanism, attribs:
                                    {\tt diam={\sl expr};
                                         circle={\sl circle attribs};}\\
                                   {\tt GX}: box control mechanism, attribs:
                                    {\tt lgth={\sl expr}; wdth={\sl expr};
                                         box={\sl box attr};}
                                    {\tt text={\sl char};}\\
                                   {\tt H}: time delay closing\\
                                   {\tt uH}: time delay opening\\
                                   {\tt HH}: time delay opening and closing\\
                                   {\tt K}: vertical closing contact line
                                     use {\tt WdBK} for a normally-closed
                                     switch\\
                                   {\tt L}: limit\\
                                   {\tt M}: maintained (latched)\\
                                   {\tt MM}: momentary contact on make\\
                                   {\tt MR}: momentary contact on release\\
                                   {\tt MMR}: momentary contact on make and
                                     release\\
                                   {\tt O}: hand operation button\\
                                   {\tt P}: pushbutton\\
                                   {\tt Pr[T|M]}: proximity (touch-sensitive or
                                       magnetically controlled)\\
                                   {\tt R}: time-delay operating arm\\
                                   {\tt Sd}: Switch-disconnector\\
                                   {\tt Th}: thermal control linkage\\
                                   {\tt Tr}: tripping\\
                                   {\tt W}: baseline with gap\\
                                   {\tt Y}: pull switch\\
                                   {\tt Z}: turn switch
   \seesect{Twoterminal:}}%
\macrodef{dtee}{dtee}{([L|R], {\sl line thickness}, {\sl attributes})}%
  {darrow}%
  {Double arrow tee junction with tail to left,
   right, or (default) back along current direction, leaving the current
   location at the tee centre; e.g.,
   {\tt dline(right\_,{,}t); dtee(R);
    \{ darrow(down\_,t) \}; darrow(right\_,t)}.
   The attributes are
     {\tt thick={\sl expr};} (line thickness in drawing units),
     {\tt innershade=({\sl r,g,b})|"{\sl color}";}
     {\tt outline=({\sl r,g,b})|"{\sl color}";}. }%
\macrodef{dtor\_}{dtor_}{}%
  {gen}%
  {degrees to radians conversion constant}%
\macrodef{dturn}{dturn}{({\sl degrees ccw},{\sl line thickness},
  {\sl attributes})}%
  {darrow}%
  {Tturn dline arg1 degrees left (ccw).
  Attributes can be
    {\tt outline=({\sl r, g, b})|"{\sl color}";}
    {\tt innershade=({\sl r, g, b})|"{\sl color}";}
    where rgb values in parentheses or a defined color is specified.}%

\Letter{E}%

\macrodef{earphone}{earphone}{( U|D|L|R|{\sl degrees, size})}%
  {cct}%
  {earphone, {\sl In1} to {\sl In3} defined
   \seesect{Composite:}}%
\macrodef{ebox}{ebox}{(\linespec,{\sl lgth},{\sl wdth},{\sl fill value},
  {\sl box attributes})}%
  {cct}%
  { two-terminal box element with adjustable dimensions and fill
   value 0 (black) to 1 (white). {\sl lgth} (length) and {\sl wdth} (width)
   are relative
   to the direction of \linespec. Alternatively, argument 1 is the
   \linespec\ and argument 2 is a semicolon-separated sequence of key=value
   terms.  The possible keys are {\tt lgth, wdth, text, box},
   e.g., {\tt lgth=0.2; text=\char34{}XX\char34;
     box=shaded \char34{}green\char34}\seesect{Twoterminal:}}%
\macrodef{E\_\_}{E__}{}%
  {gen}%
  {the constant $e$}%
\macrodef{e\_}{e_}{}%
  {gen}%
  {.e relative to current direction}%
\macrodef{e\_fet}{e_fet}{(\linespec,R,P,E|S)}%
  {cct}%
  {left or right, N or P enhancement MOSFET, normal
   or simplified, without or with envelope
    \seesect{Semiconductors:}}%
\macrodef{elchop}{elchop}{({\sl Name1,Name2})}%
  {gen}%
  {{\tt chop} for ellipses: evaluates to {\tt chop} $r$ where $r$ is
    the distance from the centre of ellipse Name1 to the intersection of
    the ellipse with a line to location Name2;
    e.g., {\tt line from A to E elchop(E,A)}}%
\macrodef{eleminit\_}{eleminit_}{(\linespec)}%
  {cct}%
  {internal line initialization}%
\macrodef{elen\_}{elen_}{}%
  {cct}%
  {default element length}%
\macrodef{ellipsearc}{ellipsearc}{({\sl width, height, startangle, endangle,
   rotangle, {\tt cw|ccw}, line attributes})}%
  {gen}%
  {Arc of a rotated ellipse in a {\tt [ ]} block. Angles are in radians.
   Arg5 is the angle of the width axis;
   e.g., {\tt ellipsearc(2,1,0,pi\_,pi\_/4,{},dashed ->)}.  Internal locations
   are {\tt Start, End, C} (for centre). }%
\macrodef{em\_arrows}{em_arrows}{({\sl type}|{\sl keys, angle, length})}%
  {cct}%
  { Radiation arrows: {\sl type} {\tt N|I|E [D|T]}:\\
  {\tt N}: nonionizing,\\
  {\tt I}: ionizing,\\
  {\tt E}: simple;\\
  {\tt D}: dot on arrow stem;\\
  {\tt T}: anchor tail;\\
  {\sl keys:} {\tt type=}{\sl chars} as above;\\
  {\tt angle=}{\sl degrees}; (absolute direction)\\
  {\tt lgth=}{\sl expr};\\
  {\tt sep=}{\sl expr}; arrow separation
  \seesect{Twoterminal:}}%
\macrodef{endshade}{endshade}{}%
  {gen}%
  {end gray shading, see {\tt beginshade}}%
\macrodef{Equidist3}{Equidist3}{({\sl Pos1, Pos2, Pos3, Result, distance})}%
  {gen}%
  {Calculates location named {\sl Result} equidistant from the first three
   positions, i.e.\ the centre of the circle passing through the three
   positions.  If arg5 is nonblank, it is returned equated to the radius.}%
\macrodef{expe}{expe}{}%
  {gen}%
  {exponential, base $e$}%

\Letter{F}%

\macrodef{f\_box}{f_box}{({\sl boxspecs},{\sl text},{\sl expr1},$\cdots$)}%
  {gen}%
  {like {\tt s\_box} but the text is overlaid on a box of identical size.
   If there is only one argument then the default box
   is invisible and filed white
    \seesect{Interaction:}}%
\macrodef{Fector}{Fector}{({\sl x1,y1,z1,x2,y2,z2})}%
  {3D}%
  {vector projected on current view plane with top face
   of 3-dimensonal arrowhead normal to x2,y2,z2 }%
\macrodef{Fe\_fet}{Fe_fet}{(\linespec,R,{\sl chars})}%
  {cct}%
  {FET with superimposed ferroelectric symbol. Args 1 to 3 are as for
   the {\tt mosfet} macro
    \seesect{Semiconductors:}}%
\macrodef{FF\_ht}{FF_ht}{}%
  {cct}%
  {flipflop height parameter in {\tt L\_unit}s, default 18}%
\macrodef{FF\_wid}{FF_wid}{}%
  {cct}%
  {flipflop width parameter in {\tt L\_unit}s, default 12}%
\macrodef{fill\_}{fill_}{({\sl number})}%
  {gen}%
  {fill macro, 0=black, 1=white\seesect{Semiconductors:}}%
\macrodef{findroot}{findroot}{%
  ({\sl function name, left bound, right bound, tolerance, variable}))}%
  {dpictools}%
  {$\;\;$ Solve $\hbox{\sl function}(x) = 0$ by the method of 
   bisection.  The calculated value is assigned to the variable named in the
   last argument (\SR{Libraries:}). Example:
   {\tt define parabola \{ \$2 = (\$1)\char94{}2 - 1 \};
   findroot( parabola, 0, 2, 1e-8, x )}. }%
\macrodef{fitcurve}{fitcurve}{(V, n, {\sl attributes,} m (default 0))}%
  {gen}%
  {Draw a spline through positions V[m], \ldots V[n]: Works only with dpic.}%
\macrodef{FlipFlop}{FlipFlop}{(D|T|RS|JK,{\sl label},{\sl boxspec},%
 {\sl pinlength})}%
  {log}%
  {flip-flops,
  {\sl boxspec} e.g.,\ ht x wid y \seesect{Logicgates:}}%
\macrodef{FlipFlopX}{FlipFlopX}{({\sl boxspec, label, leftpins, toppins,
   rightpins, bottompins, pinlength})}%
  {log}%
  {General flipflop.
   Arg 1 modifies the box (labelled Chip) default specification.
   Each of args 3 to 6 is null or a string of {\sl pinspecs}
   separated by semicolons ({\tt;}).  A {\sl Pinspec} is either empty
   or of the form
   {\tt[}{\sl pinopts}{\tt]:[}{\sl label}{\tt[:}{\sl Picname}{\tt]]}.
   The first colon draws the pin.
   Pins are placed top to bottom or left to right along the box edges with
   null {\sl pinspecs} counted for placement. Pins are named by side and number
   by default; eg {\tt W1, W2, ..., N1, N2, ..., E1, ..., S1, ...} ; however,
   if {\tt:}{\sl Picname} is present in a {\sl pinspec} then {\sl Picname}
   replaces the default name.
   A {\sl pinspec} label is text placed at the pin base. Semicolons are
   not allowed in labels; use, e.g., {\tt \char92{}char59\char123\char125}
   instead.
   To put a bar over a label, use {\tt lg\_bartxt(}{\sl label}{\tt)}.
   The {\sl pinopts} are {\tt[N|L|M][E]};
   {\tt N}: pin with not circle;
   {\tt L}: active low out;
   {\tt M}: active low in;
   {\tt E}: edge trigger \seesect{Logicgates:}.\\
   Optional arg 7 is the length of pins}%
\macrodef{foreach\_}{foreach_}{(`{\sl variable}',{\sl actions},%
  {\sl value1, value2, $\ldots$})}%
  {gen}%
  {Clone of Loopover\_ by a different name:
   Repeat {\sl actions} with {\sl variable} set successively to
   {\sl value1, value2, $\ldots$}, setting macro {\tt m4Lx} to 1, 2,
   $\ldots$, terminating if {\sl variable} is nul}%
\macrodef{for\_}{for_}{({\sl start},{\sl end},{\sl increment},`{\sl actions}')}%
  {gen}%
  {integer for loop with index variable {\tt m4x} \seesect{Looping:}}%
\macrodef{FTcap}{FTcap}{({\sl chars})}%
  {cct}%
  {Feed-through capacitor; example of a composite element derived from
   a two-terminal element.  Defined points:
   {\sl .Start, .End, .C, .T1, .T2, T}\\
   Arg 1: {\tt A}:  type A (default),
   {\tt B}: type B,
   {\tt C}: type C 
   \seesect{Composite:}}%
\macrodef{fuse}{fuse}{({\sl linespec, type, wid, ht, attributes})}%
  {cct}%
  {fuse symbol, type$=$
  {\tt  A|B|C|D|S|HB|HC|SB} or {\tt dA=D}\seesect{Twoterminal:}}%

\Letter{G}%

\macrodef{gap}{gap}{(\linespec,{\sl fill},A)}%
  {cct}%
  {gap with (filled) dots, A=chopped arrow between dots\seesect{Twoterminal:}}%
\macrodef{gen\_init}{gen_init}{}%
  {gen}%
  {initialize environment for general diagrams
    (customizable, reads {\tt libgen.m4})}%
\macrodef{g\_fet}{g_fet}{(\linespec,R,P,{\sl shade spec})}%
  {cct}%
  {left or right, N or P graphene FET, without or with shading
    \seesect{Semiconductors:}}%
\macrodef{g\_}{g_}{}%
  {gen}%
  {green color value}%
\macrodef{G\_hht}{G_hht}{}%
  {log}%
  {gate half-height in {\tt L\_unit}s, default 3}%
\macrodef{geiger}{geiger}{(\linespec, r, {\sl diameter}, R,
  {\sl body attributes, body name})}%
  {cct}%
  {Wrapper that calls {\tt source} with identical arguments except 
   arg2, which is blank or {\tt r} for right orientation.} 
%\macrodef{glabel\_}{glabel_}{}%
%  {cct}%
%  {internal general labeller}%
%\macrodef{gpar\_}{gpar_}{({\sl element},{\sl element},{\sl separation})}%
%  {cct}%
%  {two same-direction elements in parallel}%
\macrodef{gpolyline\_}{gpolyline_}{({\sl fraction}, {\sl location}, ...)}%
  {gen}%
  {internal to {\tt gshade}}%
\macrodef{graystring}{graystring}{({\sl gray value})}%
  {gen}%
  {evaluates to a string compatible with the postprocessor in use
   to go with {\tt colored}, {\tt shaded}, or {\tt outlined} attributes.
   (PSTricks, metapost, pgf-tikz, pdf, postscript, svg).
   The argument is a fraction in the range $[0,1]$; see {\tt rgbstring}}%
\macrodef{grid\_}{grid_}{({\sl x},{\sl y})}%
  {log}%
  {absolute grid location}%
\macrodef{ground}{ground}{(at {\sl location}, T|{\sl stem length},
   N|F|S|L|P[A]|E, U|D|L|R|{\sl degrees})}%
  {cct}%
  { ground, without stem for 2nd arg = T;\\
    {\tt N}: normal,\\
    {\tt F}: frame,\\
    {\tt S}: signal,\\
    {\tt L}: low-noise,\\
    {\tt P}: protective,\\
    {\tt PA}: protective alternate,\\
    {\tt E}: European; up, down, left, right, or angle
    from horizontal (default -90) \\
   \seesect{Composite:}}%
\macrodef{gshade}{gshade}{({\sl gray value},A,B,...,Z,A,B)}%
  {gen}%
  {(Note last two arguments).  Shade a polygon with named
    vertices, attempting to avoid sharp corners}%
\macrodef{gyrator}{gyrator}{({\sl box specs,space ratio,pin lgth,}[N][V])}%
  {cct}%
  {Gyrator two-port wrapper for {\tt nport}, {\tt N} omits pin dots; {\tt V}
   gives a vertical orientation
   \seesect{Composite:}}%

\Letter{H}%

\macrodef{hatchbox}{hatchbox}{({\sl boxspec,hashsep,hatchspec,angle})
  {\rm or} hatchbox({\sl keys})}%
  {gen}%
  { If Arg1 contains keys then a box is drawn in the current direction
    or as specified by {\tt boxdir}; otherwise the box is drawn to the right.
    The hatch lines are at {\tt angle} with respect to the current direction
    (default 45 degrees).
   Defined keys are:\\
    {\tt wid={\sl expr};}\\
    {\tt ht={\sl expr};}\\
    {\tt box={\sl attributes};} (e.g. {\tt dashed outline "{\sl color}"})\\
    {\tt hatchsep={\sl expr};}\\
    {\tt hatchspec={\sl attributes};}\\
    {\tt angle={\sl degrees};}\\
    {\tt boxdir={\sl degrees};}\\
 e.g.,
   {\tt hatchbox(outlined "blue",{},dashed outlined "green" thick 0.4)};\\
   also
   {\tt define mycolor \lbr{}rgbstring(1,0.2,0.5)\rbr;\\ 
        hatchbox(box=dashed outlined mycolor)}}%
\macrodef{Header}{Header}{(1|2,{\sl rows,wid,ht,box attributes})}%
  {log}%
  {Header block with 1 or 2 columns and square Pin 1:
   arg1 = number of columns;
   arg2 = pins per column;
   arg3,4 = custom wid, ht;
   arg5 = e.g., {\tt fill\_(0.9)}%
    \seesect{Composite:}}%
\macrodef{HeaderPin}{HeaderPin}{({\sl location, type, Picname},%
n|e|s|w,{\sl length})}%
  {log}%
  {General pin for {\tt Header} macro; arg 4 specifies pin direction
   with respect to the current drawing direction)}%
\macrodef{heatere}{heatere}{({\sl linespec, keys,} [R][T])}%
  {cct}%
  {Heater element with curved sides\seesect{Twoterminal:}.
    {\tt R} means right orientation;
    {\tt T} truncates leads to the width of the body.
    The {\sl keys} for the body are\\
    {\tt lgth={\sl expr};}
    {\tt wdth={\sl expr};} (default {\tt lgth*2/5});
    {\tt cycles={\sl expr};}%
    {\tt line={\sl attributes};} (e.g., {\tt dotted, dashed, outlined})}%
\macrodef{heater}{heater}{({\sl linespec, ndivisions|keys, wid, ht,
    boxspec}|[E[R][T]])}%
  {cct}%
  {Heater element\seesect{Twoterminal:}. If arg 5 contains {\tt E,}
    draws an {\tt heatere({\sl linespec, keys,} [R][T]),}
    otherwise a
    {\tt heatert({\sl linespec, nparts, wid, ht, boxspec})}}%
\macrodef{heatert}{heatert}{({\sl linespec, nparts|keys, wid, ht, boxspec})}%
  {cct}%
  {Two-terminal rectangular heater element\seesect{Twoterminal:}.
    The {\sl keys} for the body are
    {\tt parts={\sl expr};}
    {\tt lgth={\sl expr};}
    {\tt wdth={\sl expr};} (default {\tt lgth*2/5});
    {\tt box={\sl body attributes};}
      (e.g., {\tt dotted, dashed, outlined, shaded}).
    Args 3--5 are unused if any key is given}%
\macrodef{heatsink}{heatsink}{(at {\sl position, keys,} U|D|L|R|{\sl degrees})}%
  {cct}%
  {Heatsink symbol drawn beside an element.
   {\sl keys:} {\tt lgth={\sl expr;} hght={\sl expr;} fin={\sl attributes;}
     base={\sl attributes;} fincount={\sl expr;}}
     Arg3: drawing direction (default {\tt R}) }%
\macrodef{hexadecimal\_}{hexadecimal_}{($n$, [$m$])}%
  {gen}%
  {hexadecimal representation of $n,$ left padded to $m$ digits if the second
   argument is nonblank}%
\macrodef{hex\_digit}{hex_digit}{($n$)}%
  {gen}%
  {hexadecimal digit for $0 \leq n < 16$}%
\macrodef{H\_ht}{H_ht}{}%
  {log}%
  {hysteresis symbol dimension in {\tt L\_unit}s, default 2}%
\macrodef{histbins}{histbins}{({\sl data-array name, n, min, max, nbins,
  bin array name})}%
  {dpictools}%
  {$\;\;$ Generate the distribution of {\sl n} values in {\sl data-array}.
    If given, arg3 and arg4 specify maximum and minimum data values,
    otherwise they are calculated. Bins have index 0 to arg5-1.}%
\macrodef{hlth}{hlth}{}%
  {gen}%
  {current line half thickness in drawing units}%
\macrodef{hoprad\_}{hoprad_}{}%
  {cct}%
  {hop radius in crossover macro}%
\macrodef{hsvtorgb}{hsvtorgb}{({\sl h, s, v, r, g, b})}%
  {dpictools}%
  {$\;\;$ hsv color triple to rgb; {\sl h} has range 0 to 360.}%
\macrodef{ht\_}{ht_}{}%
  {gen}%
  {height relative to current direction}%

\Letter{I}%

\macrodef{ifdpic}{ifdpic}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if dpic has been specified as pic processor}%
\macrodef{ifgpic}{ifgpic}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if gpic has been specified as pic processor}%
\macrodef{ifinstr}{ifinstr}{({\sl string},{\sl string},{\sl if true},{\sl
    if false})}%
  {gen}%
  {test if the second argument is a substring of the first; also
  {\tt ifinstr({\sl string},{\sl string},{\sl if true},{\sl
  string},{\sl string},{\sl if true}, $\ldots$ {\sl if false})} }%
\macrodef{ifmfpic}{ifmfpic}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if mfpic has been specified as pic post-processor}%
\macrodef{ifmpost}{ifmpost}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if MetaPost has been specified as pic post-processor}%
\macrodef{ifpgf}{ifpgf}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if \TPGF~has been specified as pic post-processor}%
\macrodef{ifpostscript}{ifpostscript}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if Postscript ({\tt dpic -r}) has been specified as pic output format}%
\macrodef{ifpsfrag}{ifpsfrag}{({\sl if true},{\sl if false})}%
  {gen}%
  {Test if either {\tt psfrag} or {\tt psfrag\_} has been defined. For
   postscript with psfrag strings, one or the other should be defined
   prior to or at the beginning of the diagram}%
\macrodef{ifpstricks}{ifpstricks}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if \PSTricks~has been specified as post-processor}%
\macrodef{ifroff}{ifroff}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if {\bf troff} or {\bf groff} has been specified as post-processor}%
\macrodef{ifxfig}{ifxfig}{({\sl if true},{\sl if false})}%
  {gen}%
  {test if Fig 3.2 ({\tt dpic -x}) has been specified as pic output format}%
\macrodef{igbt}{igbt}{(\linespec,L|R,[L][[d]D])}%
  {cct}%
  {left or right IGBT, L=alternate gate type, D=parallel diode,
   dD=dotted connections }%
\macrodef{incircle}{incircle}{({\sl Vertex, Vertex, Vertex, InCentre, inrad})}%
  {gen}%
  {Calculate the centre {\sl InCentre} and radius {\sl inrad}
   of a circle inscribed in the triangle with the thee vertices. e.g.,
   {\tt incircle(A,B,C,Ctr,rc); circle rad rc at Ctr}}%
\macrodef{indicator}{indicator}{({\sl args 1--6 of {\tt source}}, {\sl keys})}%
  {cct}%
  {Wrapper that calls {\tt source} with up to 6 identical
    arguments and adds 4 rays.
    The {\sl keys} in arg7 are: {\tt len=}{\sl expr};
        {\tt ray=}{\sl attributes}; (of the 4 rays)}%
\macrodef{inductor}{inductor}{(\linespec, W|L, {\sl cycles}, M[n]|P[n]|K[n],
   {\sl loop wid})}%
  {cct}%
  {inductor, arg2: (default narrow), {\tt W}: wide, {\tt L}: looped;\\
   arg3: number of arcs or cycles (default 4);\\
   arg4:
   {\tt M}: magnetic core,
   {\tt P}: powder (dashed) core,
   {\tt K}: long-dashed core,
     n={\sl integer} (default 2) number of core lines named
     {\sl M4Core1, M4Core2,} $\ldots$;\\
   arg5: loop width (default {\tt L, W}: {\tt dimen\_}/5;
     other: {\tt dimen\_}/8)
   \seesect{Twoterminal:}}%
\macrodef{in\_\_}{in__}{}%
  {gen}%
  {absolute inches}%
\macrodef{inner\_prod}{inner_prod}{({\sl linear obj},{\sl linear obj})}%
  {gen}%
  {inner product of (x,y) dimensions of two linear objects}%
\macrodef{integrator}{integrator}{(\linespec,{\sl size})}%
  {cct}%
  {integrating amplifier\seesect{Twoterminal:}}%
\macrodef{intersect\_}{intersect_}{({\sl line1}.start,{\sl line1}.end,
{\sl line2}.start,{\sl line2}.end)}%
  {gen}%
  {intersection of two lines}%
\macrodef{Intersect\_}{Intersect_}{({\sl Name1},{\sl Name2})}%
  {gen}%
  {intersection of two named lines}%
\macrodef{Int\_}{Int_}{}%
  {gen}%
  {corrected (old) gpic $int()$ function}%
\macrodef{IOdefs}{IOdefs}{(\linespec,{\sl label},[P|N]*,L|R) }%
  {log}%
  {Define locations {\sl label}{\tt 1}, $\ldots$ {\sl label}{\tt n}
    along the line; {\tt P}: label only;
    {\tt N}: with {\tt NOT\_circle};
    {\tt R}: circle to right of current direction }%

\Letter{J}%

\macrodef{jack}{jack}{(U|D|L|R|{\sl degrees},{\sl chars} [;{\sl keys}])}%
  {cct}%
  {arg1: drawing direction, normally R or L;
   character sequence arg2: {\tt R}: right orientation,
   {\tt X} external make or break contact points,
   one or more {\tt L[M][B]} for L and auxiliary contacts with make or break
   points; {\tt S[M][B]} for S and auxiliary contacts;
   {\tt C[M][B]} for a centre contact
   \seesect{Composite:}}%
\macrodef{j\_fet}{j_fet}{(\linespec,L|R,P,E)}%
  {cct}%
  {left or right, N or P JFET, without or with envelope
    \seesect{Semiconductors:}}%
\macrodef{jumper}{jumper}{({\sl linespec, chars}|{\sl keys})}%
  {cct}%
  { Two-terminal solder jumper with named body parts.
    The {\sl chars} character sequence specifies the jumper components,
    and normally begins with {\tt C} and ends with {\tt D.} The character
    {\tt E} is an empty (blank) gap, {\tt J} is a filled gap, {\tt B}
    is a box component.  The components are named {\sl T1, T2, \ldots}
    Examples: {\tt CED} is a simple open jumper (the default); {\tt CJD}
    closed; {\tt CEBED} three-contact open; {\tt CJBED} three-contact
    open and closed.
    The {\sl keys} are: {\tt type=}{\sl chars} as previously;
                        {\tt body=}{\sl attributes} (e.g. {\tt fill\_(0.5)});
                        {\tt wdth=}{\sl expr};
                        {\tt name=}{\sl chars} (the body name)%
\seesect{Twoterminal:}}%

\Letter{K}%

\macrodef{KelvinR}{KelvinR}{({\sl cycles},[R],{\sl cycle wid})}%
  {cct}%
  {IEEE resistor in a {\tt [ ]} block with Kelvin taps {\sl T1} and {\sl T2}
   \seesect{Composite:}}%

\Letter{L}%

\macrodef{l\_coil}{lcoil}{({\sl \linespec, keys})}%
  {cct}%
  {Ladder-diagram coil. The keys are:
   {\tt size={\sl expr}}; (default {\tt dimen\_/3}),
   {\tt type=P|N|S|NC}; (positive, negative, set latch, negated, default blank)
   \seesect{Twoterminal:}}%
\macrodef{l\_contact}{lcontact}{({\sl \linespec, keys})}%
  {cct}%
  {Ladder-diagram contact. The keys are:
   {\tt wid={\sl expr}}; (default {\tt dimen\_/6}),
   {\tt ht={\sl expr}}; (default {\tt dimen\_/3}),
   {\tt type=P|N|NC}; (positive, negative, no contact, default blank)
   \seesect{Twoterminal:}}%
\macrodef{lamp}{lamp}{(\linespec, [R][T])}%
  {cct}%
  {Two-terminal incandescent lamp. {\tt T} truncates leads to the body width.
   \seesect{Twoterminal:}}%
\macrodef{langle}{langle}{({\sl Start, End})}%
  {gen}%
  {Angle in radians from horizontal of the line from {\sl Start}
  to {\sl End}.}%
\macrodef{larrow}{larrow}{({\sl label},{\tt ->|<-},{\sl dist})}%
  {cct}%
  {arrow {\sl dist} to left of last-drawn 2-terminal element
   \seesect{Branchcurrent:}}%
\macrodef{lbox}{lbox}{({\sl wid}, {\sl ht}, {\sl attributes}, [r={\sl expr}])}%
  {gen}%
  {box oriented in current direction, arg 3= e.g.\ {\tt dashed shaded "red"}.
   Arg 4 specifies box corner radius.}%
\macrodef{LCintersect}{LCintersect}{({\sl line name, Centre, rad,} [R],
  [{\sl Line start, End}])}%
  {gen}%
  { First (second if arg4 is R) intersection of a line with a circle.
    Solves $|V.{\tt start} + tV| = {\sl radius}$ for $t$ where $V$ is the line.
    If arg1 is blank then the line start and end are given in arg5 and arg6.}%
\macrodef{LCtangent}{LCtangent}{({\sl Pos1, Centre, rad,} [R])}%
  {gen}%
  { Left (right if arg4=R) tangent point of line
     from Pos1 to circle at Centre with radius arg3}%
\macrodef{left\_}{left_}{}%
  {gen}%
  {left with respect to current direction \seesect{Placing:}}%
\macrodef{LEintersect}{LEintersect}{({\sl line name, Centre, ellipse wid,
  ellipse ht}, [R], [{\sl Line start, End}])}%
  {gen}%
  { First (second if arg5 is R) intersection of a line with an ellipse.
    If arg1 is blank then the line start and end are given in arg6 and arg7.}%
\macrodef{length3}{length3}{({\sl vector})}%
  {dpictools}%
  {$\;\;$ Euclidean length of 3-vector argument.}%
\macrodef{length3D}{length3D}{(x,y,z)}%
  {3D}%
  {Euclidean length of triple x,y,z}%
\macrodef{LEtangent}{LEtangent}{({\sl Pos1, Centre, ellips wid, ellipse ht,}
 [R])}%
  {gen}%
  { Left (right if arg5=R) tangent point of line
     from Pos1 to ellipse at Centre with given width and height}%
\macrodef{lg\_bartxt}{lg_bartxt}{}%
  {log}%
  {draws an overline over logic-pin text (except for xfig)}%
\macrodef{lg\_pin}{lg_pin}{({\sl location, label, Picname},
  n|e|s|w[L|M|I|O][N][E], {\sl pinno, optlen})}%
  {log}%
  {comprehensive logic pin;\\
   {\sl label}: text (indicating logical pin function, usually),\\
   {\sl Picname}: pic label for referring to the pin (line),\\
   {\tt n|e|s|w}: orientation (north, south, east, west),\\
   {\tt L}: active low out,\\
   {\tt M}: active low in,\\
   {\tt I}: inward arrow,\\
   {\tt O}: outward arrow,\\
   {\tt N}: negated,\\
   {\tt E}: edge trigger}%
\macrodef{lg\_pintxt}{lg_pintxt}{}%
  {log}%
  {reduced-size text for logic pins}%
\macrodef{lg\_plen}{lg_plen}{}%
  {log}%
  {logic pin length in in {\tt L\_unit}s, default 4}%
\macrodef{LH\_symbol}{LH_symbol}{([U|D|L|R|{\sl degrees}][I],{\sl keys})}%
  {log}%
  {logic-gate hysteresis symbol; {\tt I:} inverted. The keys are:
    {\tt lgth={\sl expr};}, 
    {\tt wdth={\sl fraction};} i.e. body width ={\sl fraction $\times$ height}}%
\macrodef{lin\_ang}{lin_ang}{({\sl line-reference}[,d])}%
  {gen}%
  {the angle of a line or move from {\tt .start} to {\tt .end} of a linear
   object (in degrees if arg2={\tt d})}%
\macrodef{linethick\_}{linethick_}{({\sl number})}%
  {gen}%
  {set line thickness in points}%
\macrodef{lin\_leng}{lin_leng}{({\sl line-reference})}%
  {gen}%
  {length of a line, equivalent to {\sl line-reference}{\tt .len}
   with dpic}%
\macrodef{ljust\_}{ljust_}{}%
  {gen}%
  {ljust with respect to current direction}%
\macrodef{llabel}{llabel}{( {\sl label}, {\sl label}, {\sl label},
    {\sl relative position}, {\sl block name})}%
  {cct}%
  {Triple label on the left of the body of an element with respect to the
    current direction \seesect{Labels:}.  Labels are placed at the
    beginning, centre, and end of the last {\tt []} block (or a {\tt []} block
    named or enumerated in arg5). Each label is treated as math by
    default, but is copied literally if it is in double quotes or defined
    by sprintf.  {\sl Arg4} can be {\tt above,} {\tt below,} {\tt left,}
    or {\tt right} to supplement the default relative position.}%
\macrodef{loc\_}{loc_}{({\sl x}, {\sl y})}%
  {gen}%
  {location adjusted for current direction}%
\macrodef{log10E\_}{log10E_}{}%
  {gen}%
  {constant $\log_{10}(e)$}%
\macrodef{loge}{loge}{}%
  {gen}%
  {logarithm, base $e$}%
\macrodef{log\_init}{log_init}{}%
  {log}%
  {initialize environment for logic diagrams
    (customizable, reads {\tt liblog.m4})}%
\macrodef{loop}{loop}{({\sl initial assignments, test, loop end, statements})}%
  {dpictools}%
  {$\;\;$ C-like loop.  Commas in arg3 and arg4 must
    be in quotes or parentheses. Example:\\
    {\tt loop(i=1, i<=3, i+=1, print i)} prints 1, 2, 3.}%
\macrodef{Loopover\_}{Loopover_}{(`{\sl variable}',{\sl actions},{\sl
  value1, value2, $\ldots$})}%
  {gen}%
  {Repeat {\sl actions} with {\sl variable} set successively to
   {\sl value1, value2, $\ldots$}, setting macro {\tt m4Lx} to 1, 2,
   $\ldots$, terminating if {\sl variable} is nul}%
\macrodef{lpop}{lpop}{({\sl xcoord}, {\sl ycoord}, {\sl radius},
{\sl fill},
  {\sl zero ht})} {gen}%
  {for lollipop graphs: filled circle with stem to
    {\tt ({\sl xcoord,zeroht})}}%
\macrodef{lp\_xy}{lp_xy}{}%
  {log}%
  {coordinates used by {\tt lg\_pin}}%
\macrodef{lswitch}{lswitch}{( \linespec, L|R, {\sl chars} )}%
  {cct}%
  {knife switch R=right orientation (default L=left);
    {\sl chars}: [O{\tt|}C][D][K][A] O=opening arrow; C=closing arrow;
    D=dots; K=closed switch; A=blade arrowhead \seesect{Twoterminal:}}%
\macrodef{lthick}{lthick}{}%
  {gen}%
  {current line thickness in drawing units}%
\macrodef{lt\_}{lt_}{}%
  {gen}%
  {left with respect to current direction}%
\macrodef{LT\_symbol}{LT_symbol}{(U|D|L|R|{\sl degrees},{\sl keys})}%
  {log}%
  {logic-gate triangle symbol. The keys are:
    {\tt wdth={\sl expr};}}% 
\macrodef{L\_unit}{L_unit}{}%
  {log}%
  {logic-element grid size}%

\Letter{M}%

\macrodef{m4\_arrow}{m4_arrow}{(\linespec,{\sl ht},{\sl wid})}%
  {gen}%
  {arrow with adjustable head, filled when possible}%
\macrodef{m4dupstr}{m4dupstr}{({\sl string},{\sl n},`{\sl name}')}%
  {gen}%
  {Defines {\sl name} as {\sl n} concatenated copies of {\sl
  string}.}%
\macrodef{m4lstring}{m4lstring}{({\sl arg1},{\sl arg2})}%
  {gen}%
  {expand {\sl arg1} if it begins
    with {\tt sprintf} or {\tt "}, otherwise {\sl arg2}}%
\macrodef{m4xpand}{m4xpand}{({\sl arg})}%
  {gen}%
  {Evaluate the argument as a macro}%
\macrodef{m4xtract}{m4xtract}{(`{\sl string1}',{\sl string2})}%
  {gen}%
  {delete {\sl string2} from {\sl string1}, return 1 if present}%
\macrodef{manhattan}{manhattan}{}%
  {gen}%
  {sets direction cosines for left, right, up, down}%
\macrodef{Magn}{Magn}{({\sl length, height,} U|D|L|R|{\sl degrees})}%
  {cct}%
  {magnetic action symbol.}%
\macrodef{Max}{Max}{({\sl arg, arg, $\ldots$})}%
  {gen}%
  {Max of an arbitrary number of inputs}%
\macrodef{memristor}{memristor}{({\sl linespec, wid, ht, attributes})}%
  {cct}%
  {memristor element\seesect{Twoterminal:}}%
\macrodef{microphone}{microphone}{( A|U|D|L|R|{\sl degrees, size, attributes})}%
  {cct}%
  {microphone; if arg1 = A: upright mic, otherwise arg1 sets direction
   of standard microphone with {\sl In1} to {\sl In3} defined
   \seesect{Composite:}}%
\macrodef{Min}{Min}{({\sl arg, arg, $\ldots$})}%
  {gen}%
  {Min of an arbitrary number of inputs}%
\macrodef{Mitre\_}{Mitre_}{%
 ({\sl Line1,Line2,length,line attributes})}%
  {gen}%
  {e.g., {\tt Mitre\_(L,M)} draws angle at intersection of lines
   L and M with legs of length arg3 (default {\tt linethick bp\_\_/2});
   sets {\tt Here} to intersection
    \seesect{Corners:}}%
\macrodef{mitre\_}{mitre_}{%
 ({\sl Position1,Position2,Position3,length,line attributes})}%
  {gen}%
  {e.g., {\tt mitre\_(A,B,C)} draws angle ABC with legs
   of length arg4 (default {\tt linethick bp\_\_/2}); sets {\tt Here}
   to Position2
    \seesect{Corners:}}%
\macrodef{mm\_\_}{mm__}{}%
  {gen}%
  {absolute millimetres}%
\macrodef{mosfet}{mosfet}{(\linespec,L|R,{\sl chars},E)}%
  {cct}%
  {MOSFET left or right, included components defined by characters,
  envelope.
   arg 3 chars:\\
   {\tt [u][d]B:} center bulk connection pin\\
   {\tt D:} D pin and lead\\
   {\tt E:} dashed substrate\\
   {\tt F:} solid-line substrate\\
   {\tt [u][d]G:} G pin to substrate at source\\
   {\tt [u][d]H:} G pin to substrate at center\\
   {\tt L:} G pin to channel (obsolete)\\
   {\tt [u][d]M:} G pin to channel, u: at drain end, d: at source end\\
   {\tt [u][d]M{\sl n}:} multiple gates G0 to G{\sl n}\\
   {\tt [d]Py:} parallel diode, d=reversed\\
   {\tt [d]Pz:} parallel zener diode, d=reversed\\
   {\tt O:} diode connection dots\\
   {\tt Q:} connect B pin to S pin\\
   {\tt R:} thick channel\\
   {\tt [u][d]S:} S pin and lead u: arrow up, d: arrow down\\
   {\tt [d]T:} G pin to center of channel d: not circle\\
   {\tt X:} XMOSFET terminal\\
   {\tt Z:} simplified complementary MOS
   \seesect{Semiconductors:}}%
\macrodef{Mux\_ht}{Mux_ht}{}%
  {log}%
  {Mux height parameter in {\tt L\_unit}s, default 18}%
\macrodef{Mux}{Mux}{({\sl n},{\sl label},
   {\tt [L][B|H|X][N[{\sl n}]|S[{\sl n}]][[N]OE], {\sl wid}, {\sl ht},
     {\sl attributes}})}%
  {log}%
  {binary multiplexer, $n$ inputs,
    Arg5 is of the form {\sl expr}{\tt [:{\sl expr}]}, i.e. left (input)-side
     height optionally followed by right (output)-side height;\\
    {\tt L} reverses input pin numbers,\\
    {\tt B} display binary pin numbers,\\
    {\tt H} display hexadecimal pin numbers,\\
    {\tt X} do not print pin numbers,\\
    {\tt N[{\sl n}]} puts Sel or Sel$0$ .. Sel$n$
    at the top (i.e., to the left of the drawing direction),\\
    {\tt S[{\sl n}]} puts the Sel inputs at the bottom (default)\\
    {\tt OE} ({\tt N}: negated) {\tt OE} pin \seesect{Logicgates:}}%
\macrodef{Mux\_wid}{Mux_wid}{}%
  {log}%
  {Mux width parameter in {\tt L\_unit}s, default 8}%
\macrodef{Mx\_pins}{Mx_pins}{}%
  {log}%
  {max number of gate inputs without wings, default 6}%

\Letter{N}%

\macrodef{NAND\_gate}{NAND_gate}{({\tt {\sl n}, [N][B],
   [{\sl wid}, [{\sl ht}]], {\sl attributes}})}%
  {log}%
  {`nand' gate, 2 or {\sl n\/} inputs ($0 \leq n \leq 16$);
   {\tt N}: negated inputs; {\tt B}: box shape.
   Alternatively, {\tt NAND\_gate({\sl chars}, [B], {\sl wid},
    {\sl ht}, {\sl attributes})}, where
   arg1 is a sequence of letters {\tt P|N} to define
   normal or negated inputs.
    \seesect{Logicgates:}}%
\macrodef{N\_diam}{N_diam}{}%
  {log}%
  {diameter of `not' circles in {\tt L\_unit}s, default 1.5}%
\macrodef{NeedDpicTools}{NeedDpicTools}{}%
  {gen}%
  {executes {\tt copy "HOMELIB\_/dpictools.pic"} if the file has
  not been read}%
\macrodef{neg\_}{neg_}{}%
  {gen}%
  {unary negation}%
\macrodef{ne\_}{ne_}{}%
  {gen}%
  {.ne with respect to current direction}%
\macrodef{n\_}{n_}{}%
  {gen}%
  {.n with respect to current direction}%
\macrodef{norator}{norator}{(\linespec,{\sl width},{\sl ht},{\sl attributes})}%
  {cct}%
  { norator two-terminal element \seesect{Twoterminal:}}%
\macrodef{NOR\_gate}{NOR_gate}{({\sl n},N)}%
  {log}%
  {`nor' gate, 2 or {\sl n\/} inputs; {\tt N}: negated input.
   Otherwise, arg1 can be a sequence of letters {\tt P|N} to define
   normal or negated inputs.
    \seesect{Logicgates:}}%
\macrodef{NOT\_circle}{NOT_circle}{}%
  {log}%
  {`not' circle}%
\macrodef{NOT\_gate}{NOT_gate}{(\linespec,[B][N|n],{\sl wid},{\sl height},
  {\sl attributes})}%
  {log}%
  {`not' gate.
   When {\sl linespec} is blank then the element is composite and In1,
   Out, C, NE, and SE are defined; otherwise the element is drawn as a
   two-terminal element. arg2: {\tt B}: box gate, {\tt N}: not circle at
   input and output, {\tt n}: not circle at input only
    \seesect{Logicgates:}}%
\macrodef{NOT\_rad}{NOT_rad}{}%
  {log}%
  {`not' radius ({\tt N\_rad}) in absolute drawing units}%
\macrodef{NPDT}{NPDT}{({\sl npoles,}[R])}%
  {cct}%
  {Double-throw switch; {\sl npoles:} number of poles;
   {\tt R}: right orientation with respect to drawing direction
   \seesect{Composite:}}%
\macrodef{nport}{nport}{({\sl box spec{\tt ;}other commands,
nw,nn,ne,ns,space ratio,pin lgth,style, other commands})}%
  {cct}%
  { Default is a standard-box twoport.  Args 2 to 5 are
    the number of ports to be drawn on w, n, e, s sides.  The port pins
    are named by side, number, and by a or b pin, e.g., W1a, W1b, W2a,
    $\ldots$ Arg 6 specifies the ratio of port width to interport space
    (default 2), and arg 7 is the pin length.  Set arg 8 to N to omit
    the dots on the port pins. Arguments 1 and 9 allow customizations
   \seesect{Composite:}}%
\macrodef{N\_rad}{N_rad}{}%
  {log}%
  {radius of `not' circles in {\tt L\_unit}s, default {\tt N\_diam/2}}%
\macrodef{nterm}{nterm}{({\sl box spec{\tt ;}other commands,
nw,nn,ne,ns,pin lgth,style, other commands})}%
  {cct}%
  {n-terminal box macro (default three pins).
   Args 2 to 5 are the number of pins to be drawn on W, N, E, S
   sides.  The pins are named by side and number, e.g. W1, W2, N1,
   $\ldots$ Arg 6 is the pin length.  Set arg 7 to N to omit the
   dots on the pins. Arguments 1 and 8 allow customizations, e.g.
   {\tt nterm(,{,},{,},{,}N,"\$a\$" at Box.w ljust,"\$b\$" at Box.e rjust,
      "\$c\$" at Box.s above)} }%
\macrodef{nullator}{nullator}{(\linespec,{\sl width},{\sl ht},{\sl attributes})}%
  {cct}%
  { nullator two-terminal element \seesect{Twoterminal:}}%
\macrodef{nw\_}{nw_}{}%
  {gen}%
  {.nw with respect to current direction}%
\macrodef{NXOR\_gate}{NXOR_gate}{({\sl n},N)}%
  {log}%
  {`nxor' gate, 2 or {\sl n\/} inputs; {\tt N}: negated input.
   Otherwise, arg1 can be a sequence of letters {\tt P|N} to define
   normal or negated inputs.
   The default output conforms to current ANSI standard by drawing short
   lines from the inputs to the gate main body. Original behaviour to
   omit them can be set by {\tt define(`XOR\_off',-1)} either globally
   or for individual gates.
    \seesect{Logicgates:}}%

\Letter{O}%

\macrodef{opamp}{opamp}{\tt (\linespec,{\sl label, label, size}|{\sl keys,
  chars, other commands})}%
  {cct}%
  {operational amplifier with $-,$ $+$ or other internal labels and
    specified size, drawn in a {\tt [ ]} block.
    {\sl chars:} {\tt P} add power connections {\sl V1} and {\sl V2},
    {\tt R} swap {\sl In1, In2 labels,} {\tt T} truncated point.  The internally
    defined positions are {\sl W, N, E, S, C, Out, NE, SE, In, In2}, and
    the (obsolete) positions {\sl E1 = NE, E2 = SE}. Instead of a size
    value, arg4 can be a key-value sequence.  The keys are:
    {\tt lgth={\sl expr};}, 
    {\tt wdth={\sl expr};}, 
    {\tt body={\sl attributes};}, e.g., {\tt body=shaded "{\sl color}"}. 
   \seesect{Composite:}}%
\macrodef{open\_arrow}{open_arrow}{(\linespec,{\sl ht},{\sl wid})}%
  {gen}%
  {arrow with adjustable open head}%
\macrodef{OR\_gate}{OR_gate}{({\sl n},[N][B], {\sl wid,} {\sl ht,}%
   {\sl attributes})}%
  {log}%
  {Or gate, $n$ inputs ($0 \leq n \leq 16$); arg2: {\tt N}: negated inputs;
   {\tt B}: box gate.
   Otherwise, arg1 can be a sequence of letters {\tt P|N} to define
   normal or negated inputs.
    \seesect{Logicgates:}}%
\macrodef{OR\_gen}{OR_gen}{($n$,{\sl chars},[{\sl wid},[{\sl ht}]],
   {\sl attributes})}%
  {log}%
  {General OR gate: $n$=number of inputs $(0\leq n\leq 16)$;
    {\sl chars:}%
    {\tt B}: base and straight sides;\\ 
    {\tt A}: arcs;\\
    {\tt [N]NE,[N]SE,[N]I,[N]N,[N]S}: inputs or circles;\\ 
    {\tt [N]P}: XOR arc;\\
    {\tt [N]O}: output; C=center.\\
   Otherwise, arg1 can be a sequence of letters {\tt P|N} to define
   normal or negated inputs.  If arg5 contains {\tt shaded rgbstring(...)}
   the arguments of {\tt rgbstring} may not contain parentheses.}%
\macrodef{OR\_rad}{OR_rad}{}%
  {log}%
  {radius of OR input face in {\tt L\_unit}s, default 7}%

\Letter{P}%

\macrodef{parallel\_}{parallel_}{(\char96{\sl elementspec}\char39,%
 \char96{\sl elementspec}\char39 $\ldots$)}%
  {cct}%
  { Parallel combination of two-terminal elements in a {\tt []} block.
    Each argument is a {\em quoted} elementspec of the form\\
    {\tt[Sep={\sl val};][{\sl Label}:]{\sl element};[{\sl attributes}]} where
    an {\sl attribute} is of the form\\
    {\tt[llabel($\ldots$);]|[rlabel($\ldots$);]|[b\_current($\ldots$);]}.\\
    An argument may also be {\tt series\_($\ldots$)} or {\tt
    parallel\_($\ldots$)} {\em without} attributes or quotes.  Sep={\sl
    val}; in the first branch sets the default separation of all branches
    to {\sl val}; in a later element Sep={\sl val}; applies only to
    that branch.  An element may have normal arguments but should not
    change the drawing direction.
   \seesect{Seriesandparallel:}}%
\macrodef{pconnex}{pconnex}{(R|L|U|D|{\sl degrees},{\sl chars, attributes})}%
  {cct}%
  {power connectors, arg 1: drawing direction; {\sl chars:}\\
   {\tt R} (right orientation)\\
   {\tt M|F} (male, female)\\
   {\tt A[B]|AC} (115V 3-prong, B: default box, C: circle)\\
   {\tt P} (PC connector)\\
   {\tt D} (2-pin connector)\\
   {\tt G|GC} (GB 3-pin)\\
   {\tt J} (110V 2-pin)
    \seesect{Composite:}}%
\macrodef{pc\_\_}{pc__}{}%
  {gen}%
  {absolute points}%
\macrodef{perpto}{perpto}{({\sl Pos1, Line, Point})}%
  {gen}%
  {{\sl Point} is the label for the point on {\sl Line} of the
  perpendicular
   from {\sl Point} to {\sl Line}.}%
\macrodef{Pconn}{Pconn}{([$-$]{\sl n},U|D|L|R|{\sl degrees}[:{\sl length}],
  {\sl chars}|{\sl keys})}%
  {cct}%
  { Multiple {\tt tconn} connectors nameed {\sl T1} to {\sl Tn} in a {\tt [ ]}
    block.
    A negative arg1 reverses pin numbers {\sl n} to 1 instead of 1 to {\sl n}.
   Arg2 specifies the drawing direction (up, down, left, right, angle) and,
   if {\tt :}{\sl expression} is appended, the length of the pins. 
   The permissible {\sl chars} are as for {\tt tconn}:
   {\tt > | >{}> | < | <{}< | A | AA | M | O | OF}.
   Type {\tt O} draws a node (circle); {\tt OF} a filled circle.
   Type {\tt M} is a black bar; {\tt A} is an open arc end; type {\tt AA}
   a double open arc.  Type {\tt >} (the default) is an arrow-like output
   connector; {\tt <} and {\tt <{}<} input connectors.
   The keys are {\tt type=}{\sl chars} as above;
   {\tt wdth=}{\sl expr}; {\tt lgth=}{\sl expr}; {\tt sep=}{\sl expr};
   {\tt head=}{\sl attributes except} {\tt lgth, wdth.}
   The key {\tt sep=} is the double-head separation.
   Additionally, the key {\tt pitch=}{\sl expr} specifies connector
   separation.
    \seesect{Composite:}}%
\macrodef{PerpTo}{PerpTo}{({\sl Pos1, Pos2, Pos3})}%
  {gen}%
  {The point between Pos2 and Pos3 of intersection of the perpendicular
   to Pos1, i.e., the perpendicular projection of Pos1 onto the line
   from Pos2 to Pos3.}%
\macrodef{pi\_}{pi_}{}%
  {gen}%
  {$\pi$}%
\macrodef{plug}{plug}{\smash{(U|D|L|R|{\sl degrees},[2|3][R])}}%
  {cct}%
  {Phone plug; arg1: drawing direction; arg2: {\tt R} right orientation,
   {\tt 2|3} number of conductors\seesect{Composite:}}%
\macrodef{pmod}{pmod}{({\sl integer}, {\sl integer})}%
  {gen}%
  {+ve $\hbox{mod}(M,N)$ e.g., $\hbox{\tt pmod}(-3,5)=2$}%
\macrodef{point\_}{point_}{({\sl angle})}%
  {gen}%
  {(radians) set direction cosines}%
\macrodef{Point\_}{Point_}{({\sl integer})}%
  {gen}%
  {sets direction cosines in degrees \seesect{Placing:}}%
\macrodef{polar\_}{polar_}{({\sl x},{\sl y})}%
  {gen}%
  {rectangular-to polar conversion}%
\macrodef{polygon}{polygon}{({\sl n},{\sl keys})}%
  {gen}%
  {Regular polygon in a {\tt []} block. The keys are
    {\tt line={\sl line attributes};} (e.g., {\tt dashed shaded "blue"}),
    {\tt rot={\sl degrees};} (angle of first internal vertex {\tt V[0]}),
    {\tt side|rad={\sl expression};} size by side length or by radius.
    {\tt radv={\sl expression};} radius of rounded vertices. If this is
    nonzero then any fill has to be by {\tt rgbfill(r,g,b,polygon(...)).}
   The internal defined points are the centre {\tt C} and vertices
   {\tt V[0]} $\ldots$ {\tt V[{\sl n}]}. }%
\macrodef{posarray}{posarray}{({\sl Name, Position1, Position2, \ldots})}%
  {dpictools}%
  {$\;\;$  Populate a singly-subscripted array of positions:
    {\tt {\sl Name}[1]:{\sl Position1;}
         {\sl Name}[2]={\sl Position2;} \ldots}.}%
\macrodef{posarray2}{posarray2}{({\sl Name, expr, Position1, Position2,
  \ldots})}%
  {dpictools}%
  {$\;\;$  Populate a doubly-subscripted array of positions:
    {\tt {\sl Name}[{\sl expr},1]={\sl Position1;}
         {\sl Name}[{\sl expr},2]={\sl Position2;} \ldots}.}%

\macrodef{potentiometer}{potentiometer}{(\linespec,%
  {\sl cycles},{\sl fractional pos},{\sl length},$\cdots$)} {cct}%
  {resistor with taps T1, T2, $\ldots$
    with specified fractional positions and lengths (possibly neg)
   \seesect{Composite:}}%
\macrodef{print3D}{print3D}{(x,y,z)}%
  {3D} {write out triple for debugging}%
\macrodef{prod\_}{prod_}{({\sl a},{\sl b})}%
  {gen}%
  {binary multiplication}%
\macrodef{project}{project}{({\sl x},{\sl y},{\sl z})}%
  {3D}%
  {3D to 2D projection onto the plane perpendicular to the view
  vector {\tt View3D} with angles defined by
  {\tt setview({\sl azimuth, elevation, rotation})}.}%
\macrodef{Proxim}{Proxim}{({\sl size,} U|D|L|R|{\sl degrees, attributes})}%
  {cct}%
  {proximity detector with fillable body.}%
\macrodef{proximity}{proximity}{(\sl linespec)}%
  {cct}%
  {proximity detector (= {\tt consource(,P)})}%
\macrodef{psset\_}{psset_}{({\sl PSTricks settings})}%
  {gen}%
  {set PSTricks parameters}%
\macrodef{PtoL}{PtoL}{({\sl position}, U|D|L|R|{\sl degrees}, {\sl length}) }%
  {gen}%
  {Evaluates to {\tt from {\sl position} to
   {\sl position} + Rect\_({\sl length, angle}) }
   from the polar-coordinate data in the arguments }%
\macrodef{pt\_\_}{pt__}{}%
  {gen}%
  {\TeX\ point-size factor, in scaled inches, ({\tt *scale/72.27})}%
\macrodef{ptrans}{ptrans}{(\linespec, [R|L])}%
  {cct}%
  {pass transistor; {\tt L=} left orientation
    \seesect{Semiconductors:}}%
\macrodef{pushkey\_}{pushkey_}{({\sl string, key, default value,}[N])}%
  {gen}%
  {Key-value definition.
  If {\sl string} contains the substring
  {\sl key}{\tt =}{\sl expr} then macro {\tt m4{\sl key}}
  is defined using {\tt pushdef()} to
  expand to {\tt ({\sl expr})}, or to {\tt ({\sl default value})} if the
  substring is missing.  Arg 1 can contain several such substrings separated
  by semicolons.
  If arg4 is nonblank, the parentheses are omitted.
   \seesect{Macroarguments:}}%
\macrodef{pushkeys\_}{pushkeys_}{({\sl string, key sequence})}%
  {gen}%
  {Multiple key-value definitions. Arg2 is a semicolon-separated
   sequence of terms of the form {\tt {\sl key}:{\sl default-value}[:N]}
   which must contain no semicolons and the default values contain no colons.
   A key may not be the tail of another key.
   Macro {\tt pushkey\_} is applied to each of the terms in order.
   Quote arg2 for robustness and, if an argument depends on a previous
   argument, add quotes to delay expansion; for example
   {\tt pushkeys\_(\char96\$1\char39,\char96{}hght:0.5;
     wdth:m4\char96\char39hght/2\char39)}.
   \seesect{Macroarguments:}}%
\macrodef{pvcell}{pvcell}{({\sl linespec, width, height, attributes})}%
  {cct}%
  {PV cell}%
\macrodef{px\_\_}{px__}{}%
  {gen}%
  {absolute SVG screen pixels}%

\Letter{R}%

\macrodef{randn}{randn}{({\sl array name, $n,$ mean, stddev})}%
  {dpictools}%
  {$\;\;$ Assign $n$ Gaussian random numbers in array
   $\hbox{\sl name}[1], \hbox{\sl name}[2], \ldots \hbox{\sl name}[n]$
   with given mean and standard deviation.}%
\macrodef{rarrow}{rarrow}{({\sl label,{\tt ->|<-},{\sl dist}})}%
  {cct}%
  {arrow {\sl dist} to right of last-drawn 2-terminal element
   \seesect{Branchcurrent:}}%
\macrodef{r\_stub}{r_stub}{( at {\sl position, keys})}%
  {cct}%
  {microstrip radial stub. The {\sl keys} are:\\
   {\tt dir=U|D|L|R|{\sl degrees};}
    (default {\tt U}) drawing direction (see {\tt setdir\_})\\
   {\tt irad={\sl expr};} inner radius\\
   {\tt orad={\sl expr};} outer radius\\
   {\tt angle={\sl expr};} (degrees) sector angle\\
   {\tt outline=}outline attributes; (but not thickness)\\
   {\tt fill=}internal shade color;\\
   {\tt stem=T[I]|}stem attributes; {\tt T} means no stem,
   {\tt TI} means no stem and no inner arc
 \seesect{Composite:}}%
\macrodef{Rect\_}{Rect_}{({\sl radius},{\sl angle})}%
  {gen}%
  {(deg) polar-to-rectangular conversion}%
\macrodef{rect\_}{rect_}{({\sl radius},{\sl angle})}%
  {gen}%
  {(radians) polar-rectangular conversion}%
\macrodef{reed}{reed}{({\sl linespec, width, height, box attribues},
[R][C])}%
  {cct}%
  {Enclosed reed two-terminal contact;
   {\tt R}: right orientation; {\tt C}: closed contact; e.g., {\tt
   reed(,{,}dimen\_/5,shaded "lightgreen"} \seesect{Composite:}}%
\macrodef{relaycoil}{relaycoil}{({\sl chars, wid, ht,} R|L|U|D|{\sl
degrees, attributes})}%
  {cct}%
  {chars:
    {\tt X}: or default: external lines from A2 and B2;\\
    {\tt AX}: external lines at positions A1,A3;\\
    {\tt BX}: external lines at positions B1,B3;\\
    {\tt NX}: no lines at positions A1,A2,A3,B1,B2,B3;\\
    {\tt SO}: slow operating;\\
    {\tt SOR}: slow operating and release;\\
    {\tt SR}: slow release;\\
    {\tt HS}: high speed;\\
    {\tt S}:  diagonal slash;\\
    {\tt NAC}: unaffected by AC current;\\
    {\tt AC}: AC current;\\
    {\tt ML}: mechanically latched;\\
    {\tt PO}: polarized;\\
    {\tt RM}: remanent;\\
    {\tt RH}: remanent;\\
    {\tt TH}: thermal;\\
    {\tt EL}: electronic
   \seesect{Composite:}}%
\macrodef{relay}{relay}{({\sl number of poles, chars, attributes})}%
  {cct}%
  {relay: n poles (default 1),\\
    {\sl chars:} {\tt O}: normally open,\\
    {\tt C}: normally closed,\\
    {\tt P}: three position, default double throw,\\
    {\tt L}: drawn left (default),\\
    {\tt R}: drawn right,\\
    {\tt Th}: thermal.\seesect{Composite:}}%
\macrodef{resetdir\_}{resetdir_)}{}%
  {gen}%
  {resets direction set by {\tt setdir\_}}%
\macrodef{resetrgb}{resetrgb}{}%
  {gen}%
  {cancel {\tt r\_, g\_, b\_} color definitions}%
\macrodef{resistor}{resistor}{(\linespec, cycles, {\sl chars},
    {\sl cycle wid})}%
  {cct}%
  {resistor, number of cycles given by arg2 (default 3), {\sl chars:}\\
    {\tt AC}: general complex element,\\
    {\tt E}: {\tt ebox},\\
    {\tt ES}: {\tt ebox} with slash,\\
    {\tt EX}: {\tt ebox} with full-size X,\\
    {\tt F}: FDNR (frequency-dependent negative resistor),\\
    {\tt Q}: offset,\\
    {\tt H}: squared,\\
    {\tt LD}: light-dependent,\\
    {\tt LDE}: light-dependent ebox,\\
    {\tt N}: IEEE (default),\\
    {\tt B}: not burnable,\\
    {\tt T}: thermistor,\\
    {\tt V}: varistor variant,\\
    {\tt R}: right-oriented with respect to drawing direction;\\
    Arg4: {\sl cycle width} (default {\tt dimen\_}$/6$.)\\
    Alternative invocation:\\
      {\tt resistor(\linespec, {\sl keys})}\\
    The {\sl keys} are: semicolon (;)-separated sequence of
      {\sl key}{\tt=}{\sl value} pairs.  Allowable keys are:\\
    {\tt type={\sl chars};} as above,\\
    {\tt wdth={\sl expression};} body width,\\
    {\tt cycles={\sl integer expression};} (default 3),\\
    {\tt lgth={\sl expression};} body length (default {\tt (cycles)*(wdth)}),\\
    {\tt body={\sl attributes};} for a box body (types {\tt E, ES, AC}),\\
    {\tt env={\sl attributes};} for the envelope (types {\tt T, LD}).
   \label{resistord}\seesect{Twoterminal:}\seesect{Macroarguments:}}%
\macrodef{resized}{resized}{({\sl factor},`{\sl macro name}',args)}%
  {cct}%
  {scale the element body size by {\sl factor}}%
\macrodef{restorem4dir}{restorem4dir}{([`{\sl stack name}'])}%
  {gen}%
  {Restore m4 direction parameters from the named stack;
    default {\tt `savm4dir\_'}}%
\macrodef{reversed}{reversed}{(`{\sl macro name}',args)}%
  {cct}%
  {reverse polarity of 2-terminal element}%
\macrodef{rgbdraw}{rgbdraw}{({\sl color triple}, {\sl drawing commands})}%
  {gen}%
  {color drawing for PSTricks, pgf, MetaPost, SVG postprocessors;
   (color entries are 0 to 1),
   see {\tt setrgb} \seesect{Semiconductors:}.  Exceptionally, the color
   of SVG arrows other than the default black has to be defined using the
   {\tt outlined }{\sl string} and {\tt shaded }{\sl string} constructs.}%
\macrodef{rgbfill}{rgbfill}{({\sl color triple}, {\sl closed path})}%
  {gen}%
  {fill with arbitrary color (color entries are 0 to 1); see {\tt
   setrgb}\seesect{Semiconductors:}}%
\macrodef{rgbstring}{rgbstring}{({\sl color triple or color name})}%
  {gen}%
  {evaluates to a string compatible with the postprocessor in use
   to go with {\tt colored}, {\tt shaded}, or {\tt outlined} attributes.
   (PSTricks, metapost, pgf-tikz, pdf, postscript, svg).  The arguments
   are fractions in the range $[0,1]$; For example, {\tt box outlined
   rgbstring(0.1,0.2,0.7) shaded rgbstring(0.75,0.5,0.25)}.  For those
   postprocessors that allow it, there can be one argument which is the
   name of a defined color.
   This macro can be fragile when used as an m4 macro argument.
   Then something like the following delays expansion:\\
   {\tt define rgbpurp \lbr{}rgbstring(0.5,0,1)\rbr;}\\
   {\tt curve(,{,},rail=outlined rgbpurp)} }%
\macrodef{rgbtocmyk}{rgbtocmyk}{({\sl r, g, b, c, m, y, k})}%
  {dpictools}%
  {$\;\;$ rgb to cmyk values in the range 0 to 100.}%
\macrodef{rgbtohsv}{rgbtohsv}{({\sl r, g, b, h, s, v})}%
  {dpictools}%
  {$\;\;$ rgb color triple to hsv with {\sl h} range 0 to 360.}%
\macrodef{RightAngle}{RightAngle}{({\sl Pos1, Pos2, Pos3, line len,
  attributes})}%
  {gen}%
  {Draw a right-angle symbol at {\sl Pos2}, of size given by arg4.
   Arg5 = line attributes, e.g., {\tt outlined "gray"} or e.g. to add a dot,
    {\tt ;dot(at last line.c)}}%
\macrodef{right\_}{right_}{}%
  {gen}%
  {set current direction right \seesect{Placing:}}%
\macrodef{rjust\_}{rjust_}{}%
  {gen}%
  {right justify with respect to current direction}%
\macrodef{rlabel}{rlabel}{( {\sl label}, {\sl label}, {\sl label},
    {\sl relative position}, {\sl block name})}%
  {cct}%
  {Triple label on the right of the body of an element with respect to the
    current direction \seesect{Labels:}.  Labels are placed at the
    beginning, centre, and end of the last {\tt []} block (or a {\tt []} block
    named or enumerated in arg5). Each label is treated as math by
    default, but is copied literally if it is in double quotes or defined
    by sprintf.  {\sl Arg4} can be {\tt above,} {\tt below,} {\tt left,}
    or {\tt right} to supplement the default relative position.}%
\macrodef{RotarySwitch}{RotarySwitch}{( {\sl start degrees}, {\sl end degrees},
     {\sl keys})}%
  {cct}%
  { Rotary switch with poles drawn in a {\tt ccw} arc from {\sl start degrees}
    to {\sl end degrees} and encased in a {\tt [ ]} block.
    The keys are:\\
    {\tt poles={\sl integer};} the number of peripheral poles\\
    {\tt circle={\sl attributes};} such as rad, shaded, \ldots\\
    {\tt rad={\sl expr};} arc radius of the poles, default {\tt dimen\_}\\
    {\tt wipers={\sl wiperspec} \& {\sl wiperspec} \& \ldots;}
     A {\sl wiperspec} is either {\tt nil} or {\tt B:{\sl degrees}:{\sl length}}
     and the latter two expressions can be omitted.\\
    {\tt wline={\sl attributes};} wiper attributes (default {\tt ->})\\
    {\tt segments={\sl segspec} \& {\sl segspec} \& \ldots;}
     A {\sl segspec} is {\tt {\sl start deg}:{\sl end deg}
     :{\sl radius}:{\sl thickness}} and the latter two can be omitted.\\
    The default is {\tt RotarySwitch(-45:45,poles=4;wipers=B:45).}
    The centre dot is labeled {\sl C}, the poles are {\sl P1, P2,\ldots},
    the wipers {\sl Wiper1, Wiper2,\ldots}, and the segments
    {\sl Seg1, Seg2,\ldots}.}%
\macrodef{rot3Dx}{rot3Dx}{({\sl radians,x,y,z})}%
  {3D} {rotates x,y,z about x axis}%
\macrodef{rot3Dy}{rot3Dy}{({\sl radians,x,y,z})}%
  {3D} {rotates x,y,z about y axis}%
\macrodef{rot3Dz}{rot3Dz}{({\sl radians,x,y,z})}%
  {3D} {rotates x,y,z about z axis}%
\macrodef{rotbox}{rotbox}{({\sl wid,ht,attributes},[r|t={\sl val}])}%
  {gen}%
  {box oriented in current direction in {\tt [ ]} block;
   {\sl attributes:} e.g. {\tt dotted shaded "green".}  Defined internal
   locations: N, E, S, W (and NE, SE, NW, SW if arg4 is blank).  If arg4
   is {\tt r=}{\sl val} then corners have radius {\sl val}.  If arg4 is
   {\tt t=}{\sl val} then a spline with tension {\sl val} is used to draw
   a ``superellipse,'' and the bounding box is then only approximate. }%
\macrodef{rotellipse}{rotellipse}{({\sl wid,ht,attributes})}%
  {gen}%
  {ellipse oriented in current direction in {\tt [ ]} block;
   e.g. {\tt Point\_(45); rotellipse(,{},dotted fill\_(0.9)).} Defined
   internal locations: N, S, E, W.}%
\macrodef{Rot\_}{Rot_}{({\sl position, degrees})}%
  {gen}%
  {rotate position by degrees}%
\macrodef{rot\_}{rot_}{({\sl x, y, angle})}%
  {gen}%
  {rotate {\sl x,y} by theta radians}%
\macrodef{round}{round}{(at {\sl location,line thickness,attributes})}%
  {gen}%
  {filled circle for rounded corners; attributes={\tt colored "gray"}
   for example; leaves {\tt Here} unchanged if arg1 is blank
    \seesect{Corners:}}%
\macrodef{rpoint\_}{rpoint_}{(\linespec)}%
  {gen}%
  {set direction cosines}%
\macrodef{rpos\_}{rpos_}{({\sl position})}%
  {gen}%
  {Here + {\sl position}}%
\macrodef{r\_}{r_}{}%
  {gen}%
  {red color value}%
\macrodef{rrot\_}{rrot_}{({\sl x, y, angle})}%
  {gen}%
  {\tt Here + vrot\_({\sl x, y, cos(angle), sin(angle))}}%
\macrodef{rs\_box}{rs_box}{([angle={\sl degrees};]
     {\sl text},{\sl expr1},$\cdots$)}%
  {gen}%
  {like {\tt s\_box} but the text is rotated by {\tt text\_ang}%
   (default 90) degrees, unless
   the first argument begins with {\tt angle={\sl decimal number};},
   in which case the number defines the rotation angle.
   Two or more args are passed to {\tt sprintf()}.
   If the first argument begins with {\tt angle={\sl expr};} then
   the specified angle is used.
   The examples {\tt define(`text\_ang',45); rs\_box(Hello World)} and
   {\tt rs\_box(angle=45; Hello World)} are equivalent
   \seesect{Interaction:}, \seesect{Pstricks:}}%
\macrodef{rsvec\_}{rsvec_}{({\sl position})}%
  {gen}%
  {Here + {\sl position}}%
\macrodef{r\_text}{r_text}{({\sl degrees},{\sl text},at {\sl position})}%
  {gen}%
  {Rotate text by arg1 degrees (provides a single command for
   PSTricks, PGF, or SVG only) placed at position in arg3.
   The first argument is a decimal constant (not an expression) and
   the text is a simple string without quotes.
   \seesect{Interaction:}, \seesect{Pstricks:}}%
\macrodef{rtod\_\_}{rtod__}{}%
  {gen}%
  {constant, degrees/radian}%
\macrodef{rtod\_}{rtod_}{}%
  {gen}%
  {constant, degrees/radian}%
\macrodef{rt\_}{rt_}{}%
  {gen}%
  {right with respect to current direction}%
\macrodef{rvec\_}{rvec_}{({\sl x},{\sl y})}%
  {gen}%
  {location relative to current direction}%
\macrodef{rvec\_r}{rvec_r}{({\sl x},{\sl y})}%
  {gen}%
  {Robust location relative to current direction for use in dpic loops}%

\Letter{S}%

\macrodef{sarrow}{sarrow}{(\linespec,{\sl keys})}%
  {gen}%
  {Single-segment, single-headed special arrows with {\sl keys}:\\
       {\tt type=}{\tt O[pen]} (default)
          | {\tt D[iamond]}
          | {\tt C[rowfoot]}
          | {\tt DI} (disk)
          | {\tt P[lain]}
          | {\tt PP[lain]}
          | {\tt R[ight]}
          | {\tt L[eft]} {\tt ;}\\
       {\tt wdth=}{\sl expression}{\tt ;} (default {\tt arrowwid})\\
       {\tt lgth=}{\sl expression}{\tt ;} (default {\tt arrowht})\\
       {\tt head=}{\sl head attributes}{\tt ;} (e.g., {\tt shaded})\\
       {\tt shaft=}{\sl shaft attributes}{\tt ;} (default: head attributes)\\
       {\tt hook=[L|R|LR]} (left, right, or double hook, default none)\\
       {\tt name=}{\sl Name}{\tt ;} (default {\sl Sarrow\_})
  The {\tt PP} key creates a doubled plain arrowhead
  \seesect{Macroarguments:}}%
\macrodef{savem4dir}{savem4dir}{([`{\sl stack name}'])}%
  {gen}%
  {Stack m4 direction parameters in the named stack
    (default {\tt `savm4dir\_'})}%
\macrodef{s\_box}{s_box}{({\sl text},{\sl expr1},$\cdots$)}%
  {gen}%
  {generate dimensioned text string using {\tt\char92{}boxdims} from
    {\tt boxdims.sty}. Two or more args are passed to {\tt sprintf()}
   (default 90) degrees \seesect{Interaction:}}%

\macrodef{sbs}{sbs}{({\sl linespec, chars, label})}%
  {cct}%
  {Wrapper to place an SBS thyristor as a two-terminal element with
   {\tt [ ]} block label given by the third argument
    \seesect{Semiconductors:}}%
\macrodef{sc\_draw}{sc_draw}{({\sl dna string, chars, iftrue, iffalse})}%
  {cct}%
  {test if chars are in string, deleting chars from string}%
\macrodef{scr}{scr}{({\sl linespec, chars, label})}%
  {cct}%
  {Wrapper to place an SCR thyristor as a two-terminal element with
   {\tt [ ]} block label given by the third argument
    \seesect{Semiconductors:}}%
\macrodef{scs}{scs}{({\sl linespec, chars, label})}%
  {cct}%
  {Wrapper to place an SCS thyristor as a two-terminal element with
   {\tt [ ]} block label given by the third argument
    \seesect{Semiconductors:}}%
\macrodef{s\_dp}{s_dp}{({\sl name},{\sl default})}%
  {gen}%
  {depth of the most recent (or named) {\tt s\_box}
    \seesect{Interaction:}}%
\macrodef{series\_}{series_}{({\sl elementspec}, {\sl elementspec},
$\ldots$)}%
  {cct}%
  { Series combination in a {\tt []} block of elements
    with shortened default length.
    Each argument is an elementspec of the form\\
    {\tt[Sep={\sl val};][{\sl Label}:]{\sl element};[{\sl attributes}]} where
    an {\sl attribute} is of the form\\
    {\tt[llabel($\ldots$);]|[rlabel($\ldots$);]|[b\_current($\ldots$);]}.\\
    An argument may also be {\tt series\_($\ldots$)} or {\tt
    parallel\_($\ldots$)} {\em without} attributes or quotes.
    An element may have normal arguments but should not
    change the drawing direction.
    Internal points {\tt Start}, {\tt End}, and {\tt C} are defined
   \seesect{Seriesandparallel:} }%
\macrodef{se\_}{se_}{}%
  {gen}%
  {.se with respect to current direction}%
\macrodef{setdir\_}{setdir_}{(R|L|U|D|{\sl degrees}, {\sl default}%
    U|D|R|L|{\sl degrees})}%
  {gen}%
  {store drawing direction and set it to
    up, down, left, right, or angle in degrees (reset by {\tt
    resetdir\_}).  The directions may be spelled out, i.e., Right,
    Left, $\ldots$
   \seesect{Seriesandparallel:}}%
\macrodef{setkey\_}{setkey_}{({\sl string, key, default,}[N])}%
  {gen}%
  {Key-value definition, like {\tt pushkey\_()} but the resulting
  macro is defined using {\tt define()} rather than {\tt pushdef().}
   \seesect{Macroarguments:}}%
\macrodef{setkeys\_}{setkeys_}{({\sl string, key sequence})}%
  {gen}%
  {Multiple key-value definition using {\tt define()} rather than
   {\tt pushdef().} See macro {\tt pushkeys\_}.
   \seesect{Macroarguments:}}%
\macrodef{setrgb}{setrgb}{({\sl red value, green value, blue value},[{\sl
   name}])}%
  {gen}%
  {define colour for lines and text, optionally named (default
   {\tt lcspec}); \seesect{Semiconductors:}}%
\macrodef{setview}{setview}{({\sl azimuth degrees},{\sl elevation
   degrees}, {\sl rotation degrees})}%
  {3D} {Set projection viewpoint for the {\tt project} macro.
   The view vector is obtained by looking in along the $x$ axis,
   then rotating about $-x,$ $-y,$ and $z$ in that order.  The components
   {\tt view3D1, view3D2,} and {\tt view3D3} are defined, as well as
   positions {\tt UPx\_, UPy\_,} and {\tt UPz\_} which are the projections
   of unit vectors {\tt (1,0,0), (0,1,0),} and {\tt (0,0,1)} respectively
   onto the plane.}%
\macrodef{sfgabove}{sfgabove}{}%
  {cct}%
  {like above but with extra space}%
\macrodef{sfgarc}{sfgarc}{(\linespec,{\sl text},{\sl text
justification},cw|ccw,
    {\sl height scale factor},{\sl arc attributes})}%
  {cct}%
  {Directed arc drawn between nodes, with text label
    and a height-adjustment parameter. Example:
    {\tt sfgarc(from B to A,-B/M,below,{,}1.1,outlined "red")} }%
\macrodef{sfgbelow}{sfgbelow}{}%
  {cct}%
  {like below but with extra space}%
\macrodef{sfg\_init}{sfg_init}{({\sl default line len, node rad, arrowhd len,
  arrowhd wid}), (reads {\tt libcct.m4})}
  {cct}%
  {initialization of signal flow graph macros}%
\macrodef{sfgline}{sfgline}{(\linespec,{\sl text},{\tt
  sfgabove|sfgbelow|ljust|rjust},{\sl line attributes})}%
  {cct}%
  {Directed straight line chopped by node radius, with text label,
   e.g., {\tt sfgline(,K/M,{,}dashed colored "orange")} }%
\macrodef{sfgnode}{sfgnode}{(at {\sl location},{\sl text},above|below,{\sl
   circle attributes})}%
  {cct}%
  {small circle default white interior, with text label. The default
  label position is inside if the diameter is bigger than {\tt textht}
  and {\tt textwid}; otherwise it is {\tt sfgabove.} Options such as
  color, fill, or line thickness can be given, e.g.,
  {\tt thick 0.8 outlined "red" shaded "orange"}. }%
\macrodef{sfgself}{sfgself}{(at {\sl location}, U|D|L|R|{\sl degrees},
   {\sl text label}, {\sl text justification}, cw|ccw, {\sl scale factor},
    [-> | <- | <->], {\sl attributes})}%
  {cct}%
  {Self-loop drawn at an angle from a node,
     with text label, specified arrowheads, and a size-adjustment parameter.
     The attributes can set thickness and color, for example. }%
\macrodef{shade}{shade}{({\sl gray value},{\sl closed line specs})}%
  {gen}%
  {Fill arbitrary closed curve. Note: when producing pdf via pdflatex, line
   thickness changes within this macro must be made via the {\tt linethick}
   environment variable rather than by the {\tt thickness} line attribute}%
\macrodef{shadebox}{shadebox}{(box {\sl attributes, shade width})}%
  {gen}%
  {Box with edge shading.  Arg2 is in points. See also {\tt shaded} }%
\macrodef{shadedball}{shadedball}{({\sl radius, highlight radius,
  highlight degrees, initial gray, final gray} | ({\sl rf,gf,bf}))}%
  {3D}%
  { Shaded ball in {\tt [ ]} box.
    The highlight is by default at {\sl radius}*3/5 and angle 110 deg
    (or arg2 deg); if setlight has been invoked then its azimuth and
    elevation arguments determine highlight position.  Arg5 can be a
    parenthesized rgb color.}
\macrodef{ShadedPolygon}{ShadedPolygon}{({\sl vertexseq, line attributes,
  degrees, colorseq})} {gen}%
  {Draws the polygon specified in arg1 and
  shades the interior according
   to arg4 by drawing lines perpendicular to the angle in arg3.  The {\sl
   vertexseq} is a colon ({\tt:}) separated sequence of vertex positions
   (or names) of the polygon in cw or ccw order. A {\sl colorseq} is of
   the form 0, r0,g0,b0, {\sl frac1},r1,g1,b1, {\sl frac2},r2,g2,b2,
   \ldots 1,rn,gn,bn with $0 < \hbox{\sl frac1} < \hbox{\sl frac2} \ldots 1$ }%
\macrodef{ShadeObject}{ShadeObject}{({\sl drawroutine, n, colorseq})}%
  {dpictools}%
  {$\;\;$
  Fill an area in a {\tt []} block with graded color
  defined by {\sl colorseq,} an indexed sequence of rgb colors:
    \fra{0}{\sl,r0,g0,b0,}
    \fra{1}{\sl,r1,g1,b1,}
    \ldots
    \fra{n}{\sl,rn,gn,bn} with\\
  $0 \leq \fra{0} < \fra{1}$
   $< \fra{2} <$
   $\ldots$ 
   $\fra{n} \leq 1.$\\  
  (Often $\fra{0} = 0$ and $\fra{n} = 1.$)
  The dpic macro\\
  {\sl drawroutine{\tt(}frac, r, g, b{\tt)}}\\
  typically draws a colored line
  and must be defined according to the area to be filled.
  This routine is called $n{+}1$ times for
  $\fra{}= \fra{0},\;$
   $\fra{0} + 1/n\times(\fra{n}{-}\fra{0}),$
   $\fra{0} + 2/n\times(\fra{n}{-}\fra{0}),$
   \ldots
   \fra{n}\\
  (i.e., often
  $\fra{} = 0, 1/n, 2/n, \ldots 1$)\\
  with rgb
  arguments interpolated in hsv space between {\sl colorseq} points
  (which are specified in rgb-space).
  Example (shade a box with 101 graded-color lines):\\ 
  {\tt B: box\\
   define HorizShade \lbr\ line right B.wid \textbackslash\\
   $\;$ from (0,-(\char36{}1)*B.ht) \textbackslash\\
   $\;$ outlined rgbstring(\char36{}2,\char36{}3,\char36{}4) \rbr;}\\
  {\tt ShadeObject(HorizShade, B.ht/lthick, 0,1,0,0, 1,0,0,1) at B}.
  }%
\macrodef{shadowed}{shadowed}{(box|circle|ellipse|line,
  {\sl position spec, keys})}%
  {gen}%
  { Object with specified shadow.  {\sl possspec} is e.g.,
    {\tt with .w at ...} or {\tt at} {\sl position}.
    The {\sl keys} are
       {\tt attrib=}{\sl object attributes}{\tt ;}
       {\tt shadowthick=}{\sl expr}{\tt ;} (default {\tt linethick*)}5/4),
       {\tt shadowcolor=}{\sl string}{\tt ;} (default {\tt "gray"}),
       {\tt shadowangle=}{\sl expr}{\tt ;} (default $-45$)
       for box only: {\tt rad=}{\sl expr}{\tt ;}%
 }%
\macrodef{shielded}{shielded}{(`{\sl two-terminal element}',
  L|U, {\sl line attributes})} {cct}%
  {shielding in a {\tt [ ]} box for
  two-terminal element. Arg2= blank
    (default) to enclose the element body; L for the left side with
    respect to drawing direction, R for right. Internal points {\tt
    .Start, .End,} and {\tt .C} are defined}%
\macrodef{s\_ht}{s_ht}{({\sl name},{\sl default})}%
  {gen}%
  {height of the most recent (or named) {\tt s\_box}%
    \seesect{Interaction:}}%
\macrodef{SIdefaults}{SIdefaults}{}%
  {gen}%
  {Sets {\tt scale = 25.4} for drawing units in mm, and sets
   pic parameters {\tt lineht = 12, linewid = 12, moveht = 12,
    movewid = 12,
    arcrad = 6, circlerad = 6, boxht = 12, boxwid = 18, ellipseht = 12,
    ellipsewid = 18, dashwid = 2, arrowht = 3, arrowwid = arrowht/2,}}%
\macrodef{sidac}{sidac}{(\linespec,{\sl keys})\label{SiDAC}}%
  {cct}%
  { Silicon bilateral switch (Silicon Diode for Alternating Current);
   keys:
   {\tt size={\sl expr}};
   {\tt env=E|{\sl attributes}} (envelope attributes except for size;
     {\tt  E}=nonblank);
   {\tt symbol={\sl attributes}} (e.g. outlined "red");
   {\tt name={\sl body name}};}%
\macrodef{sign\_}{sign_}{({\sl number})}%
  {gen}%
  {sign function}%
\macrodef{sinc}{sinc}{({\sl number})}%
  {gen}%
  {the $\hbox{sinc}(x)$ function}%
\macrodef{sind}{sind}{({\sl arg})}%
  {gen}%
  {sine of an expression in degrees}%
\macrodef{s\_init}{s_init}{({\sl name})}%
  {gen}%
  {initialize {\tt s\_box} string label to {\sl name} which should
  be unique
    \seesect{Interaction:}}%
\macrodef{Sin}{Sin}{({\sl integer})}%
  {gen}%
  {sine function, {\sl integer\/} degrees}%
\macrodef{sinusoid}{sinusoid}{({\sl amplitude, frequency, phase, tmin,
  tmax, linetype})}%
  {gen}%
  {draws a sinusoid over the interval $(t_{\hbox{\scriptsize min}},
  t_{\hbox{\scriptsize max}})$;
   e.g., to draw a dashed sine curve, amplitude {\sl a},
   of {\sl n} cycles of length {\sl x} from {\sl A}, {\tt
   sinusoid(a,twopi\_*n/x,-pi\_/2,0,x,dashed) with .Start at A}}%

\macrodef{sl\_box}{sl_box}{({\sl stem linespec, keys, stem object})}%
  {SLD}%
  {One-terminal SLD element: argument 1 is a \linespec\ to define the stem
   or, in the case of a zero-length stem, one of {\tt U, D, L, R,} or an
   angle in degrees, optionally followed by {\tt at {\sl position}}.
   The position is {\sl Here} by default.

   Argument 2 contains semicolon (;)-separated key-value attributes
   of the head:
   {\tt name={\sl{}Name}} (default {\sl Head});
   {\tt lgth={\sl{}expr}};
   {\tt wdth={\sl{}expr}};
   {\tt text="{\sl{}text}"},
   {\tt box={\sl{}box pic attributes}}.

   If argument 3 is null then a plain stem is drawn; if it is of the
   form {\tt S:}{\sl keys} or {\tt S$n$:}{\sl keys} an $n$-line slash
   symbol is overlaid on the stem; otherwise the keys are for an overlaid
   breaker, so that a {\tt C} specifies a default closed breaker, {\tt
   O} an open breaker, {\tt X,} {\tt /,} or \bsl\ for these marks, or
   \MR{sl_ttbox}{\tt sl\_ttbox} key-value pairs defining box attributes
   for the breaker (default name {\sl Br})

   \seesect{SingleLine:}}%
\macrodef{sl\_breaker}{sl_breaker}{({\sl linespec,} {\tt type=[A|C][D];}%
  {\sl ttbox args})}%
  {SLD}%
  {Two-terminal SLD element:
   type {\tt A} (the default) is for a box breaker; type 
   {\tt C} for a curved breaker; adding a {\tt D} puts drawout elements
   in the input and output leads.
   Otherwise, the arguments are as for 
   \MR{sl_ttbox}{\tt sl\_ttbox}
   \seesect{SingleLine:}}%
\macrodef{sl\_busbar}{sl_busbar}{({\sl linespec, np, keys})}%
  {SLD}%
  {Composite SLD element drawn in a {\tt [ ]} block.  A busbar is
   essentially a thick straight line 
   drawn along the {\sl linespec} with positions evenly distributed
   along it.  For example,
     {\tt line right\_; sl\_busbar(, up\_ 4.5, 5) with .P3 at Here}.

   Argument 1 is a \linespec\ to define the direction and length of the
     busbar (but not its position, since it is drawn in a {\tt [ ]} block).

   Argument 2 is the number $np$ of evenly spaced positions
     $P1, P2, \ldots Pnp$ along the line with $P1$ and $Pnp$ indented
     from the ends of the line.

   Argument 3 contains semicolon (;)-separated key-value attributes
     of the line:
   {\tt port=D} (for a dot at each port position);
   {\tt line=}{\sl pic line attributes}.
   {\tt indent=}{\sl indent distance}.
   \seesect{SingleLine:}}%
\macrodef{sl\_ct}{sl_ct}{%
    ({\tt at}{\sl position},{\sl keys},{\tt R|L|U|D|}{\sl degrees})}%
  {SLD}%
  {Composite SLD element drawn in a {\tt [ ]} block:

   The keys are as follows:
   {\tt type=L|N|S[n]} (default {\tt L;} {\tt S$n$} draws an $n$-line slash
     symbol, default 2); {\tt N} means no stem);
   {\tt scale={\sl expr} (default 1.0)};
   {\tt grnd={\sl expr} attached ground at given angle
     (type {\tt S} or {\tt N}))};
   {\tt sep={\sl{}expr}};
   {\tt stemlgth={\sl{}expr}};
   {\tt wdth={\sl{}expr}};
   {\tt direct=U|D|L|R|{\sl degrees}} (drawing direction).

   Key {\tt stemlgth} is the length of the leads at the start, centre, and end,
     with labeled ends {\sl Tstart, Tc,} and {\sl Tend}.
     The {\tt L} (default) variant also defines internal labels
     Internal labels {\sl L} and {\sl C} are included.

   Key {\tt sep} is the type-{\tt S} separation from the head to the centre
     of the slash symbol.

   Key {\tt scale} allows scaling (default scale 1.0) but, with \dpic,
     the {\tt scaled} directive can also be used.
   \seesect{SingleLine:}}%
\macrodef{sl\_disk}{sl_disk}{({\sl stem linespec, keys, breaker})}%
  {SLD}%
  {One-terminal SLD element: argument 1 is a \linespec\ to define the stem
   or, in the case of a zero-length stem, one of {\tt U, D, L, R,} or an
   angle in degrees, optionally followed by {\tt at {\sl position}}.
   The position is {\sl Here} by default.

   Argument 2 contains semicolon (;)-separated key-value attributes
   of the head:
   {\tt name={\sl{}Name}} (default {\sl Head});
   {\tt text="{\sl{}text}"};
   {\tt diam={\sl{}expr}};
   {\tt circle={\sl{}circle pic attributes}}.

   Argument 3 is null for no breaker in the stem, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   \MR{sl_ttbox}{\tt sl\_ttbox}
   key-value pairs defining box attributes for the breaker
   (default name {\sl Br})
   \label{sl_disk}
   \seesect{SingleLine:}}%
\macrodef{sl\_drawout}{sl_drawout}{({\sl linespec, keys,} R)}%
  {SLD}%
  {Two-terminal SLD element: argument 1 is a \linespec\ as for ordinary
   two-terminal elements.

   Argument 2 contains semicolon (;)-separated key-value body attributes:\\
   {\tt type=T} (for truncated leads);
   {\tt lgth={\sl{}expr},}
   {\tt wdth={\sl{}expr}} (body size);
   {\tt name={\sl{}Name}} (default {\sl Body});
   {\tt line={\sl{}pic line attributes}}; (e.g., {\tt thick 2})

   Argument 3 is {\tt R} to reverse the direction of the drawn chevrons.
   \seesect{SingleLine:}}%
\macrodef{sl\_generator}{sl_generator}{({\sl stem linespec, keys, breaker})}%
  {SLD}%
  {One-terminal SLD element: argument 2 is
   {\tt type=AC|WT|BS|StatG|PV|Y|Delta} and,
   if {\tt type=PV,} the {\tt SL\_box} keys;
   otherwise, the {\tt sl\_disk} body keys.

   Argument 3 is null for no breaker in the stem, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   \MR{sl_ttbox}{\tt sl\_ttbox}
   key-value pairs defining box attributes for the breaker
   (default name {\sl Br})
   \seesect{SingleLine:}}%
\macrodef{sl\_grid}{sl_grid}{({\sl stem linespec, keys, breaker})}%
  {SLD}%
  {One-terminal SLD element: argument 1 is a \linespec\ to define the stem
   or, in the case of a zero-length stem, one of {\tt U, D, L, R,} or an
   angle in degrees, optionally followed by {\tt at {\sl position}}.
   The position is {\sl Here} by default.

   Argument 2 contains semicolon (;)-separated key-value attributes
   of the head:
   {\tt name={\sl{}Name}} (default {\sl Head});
   {\tt lgth={\sl{}expr}};
   {\tt wdth={\sl{}expr}}.

   Argument 3 is null for no breaker in the stem, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   \MR{sl_ttbox}{\tt sl\_ttbox}
   key-value pairs defining box attributes for the breaker
   (default name {\sl Br})
   \seesect{SingleLine:}}%
\macrodef{sl\_inverter}{sl_inverter}{({\sl ttbox args})}%
  {SLD}%
  {Two-terminal SLD element: the arguments are as for 
   \MR{sl_ttbox}{\tt sl\_ttbox}
   \seesect{SingleLine:}}%

\macrodef{sl\_lamp}{sl_lamp}{({\sl stem linespec, keys, breaker})}%
  {SLD}%
  {One-terminal SLD element: the arguments are as for 
   \MR{sl_disk}{\tt sl\_disk}
   \seesect{SingleLine:}}%
\macrodef{sl\_load}{sl_load}{({\sl stem linespec, keys, breaker})}%
  {SLD}%
  {One-terminal SLD element: argument 1 is a \linespec\ to define the stem
   or, in the case of a zero-length stem, one of {\tt U, D, L, R,} or an
   angle in degrees, optionally followed by {\tt at {\sl position}}.
   The position is {\sl Here} by default.

   Argument 2 contains semicolon (;)-separated key-value attributes
   of the head:
   {\tt name={\sl{}Name}} (default {\sl Head});
   {\tt lgth={\sl{}expr}};
   {\tt wdth={\sl{}expr}};
   {\tt head={\sl{}arrowhead pic attributes}}.

   Argument 3 is null for no breaker in the stem, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   \MR{sl_ttbox}{\tt sl\_ttbox}
   key-value pairs defining box attributes for the breaker
   (default name {\sl Br})
   \seesect{SingleLine:}}%
\macrodef{sl\_meterbox}{sl_meterbox}{({\sl stem linespec, keys, breaker})}%
  {SLD}%
  {One-terminal SLD element: argument 1 is a \linespec\ to define the stem
   or, in the case of a zero-length stem, one of {\tt U, D, L, R,} or an
   angle in degrees, optionally followed by {\tt at {\sl position}}.
   The position is {\sl Here} by default.

   Argument 2 contains semicolon (;)-separated key-value attributes
   of the head:
   {\tt name={\sl{}Name}} (default {\sl Head});
   {\tt lgth={\sl{}expr}};
   {\tt wdth={\sl{}expr}};
   {\tt text="{\sl{}text}"},
   {\tt box={\sl{}box pic attributes}}.

   Argument 3 is null for no breaker in the stem, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   \MR{sl_ttbox}{\tt sl\_ttbox}
   key-value pairs defining box attributes for the breaker
   (default name {\sl Br})
   \seesect{SingleLine:}}%
\macrodef{sl\_reactor}{sl_reactor}{({\sl stem linespec, keys, breaker keys,
    breaker keys})}%
  {SLD}%
  {Two-terminal SLD element: argument 1 is a \linespec\ as for ordinary
   two-terminal elements.

   Argument 2 contains semicolon (;)-separated key-value body attributes:
   {\tt name={\sl{}Name}} (default {\sl Body});
   {\tt diam={\sl{}expr}}.

   Argument 3 is null for no breaker in the input lead, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or key-value pairs as above defining breaker attributes
   except that the default breaker name is {\sl BrI}.

   Argument 4 defines the breaker in the output lead as for argument 3
   except that the default breaker name is {\sl BrO}.
   \seesect{SingleLine:}}%
\macrodef{sl\_rectifier}{sl_rectifier}{({\sl ttbox args})}%
  {SLD}%
  {Two-terminal SLD element: the arguments are as for 
   \MR{sl_ttbox}{\tt sl\_ttbox}
   \seesect{SingleLine:}}%
\macrodef{sl\_slash}{sl_slash}{(at {\sl position, keys,}%
   [$n$:]R|L|U|D|{\sl degrees})}%
  {SLD}%
  {Slash symbol for SLD elements: draws $n$ slashes in a {\tt [] } block.
   The keys are
   {\tt lines={\sl line attributes,} e.g., dotted thick {\sl expr}};
   {\tt size=}{\sl expr} (default {\tt ht dimen\_/3}).
   \seesect{SingleLine:}}%
%
\macrodef{sl\_transformer3}{sl_transformer3}{({\sl linespec, keys,
    breaker keys, symbol keys})}%
  {SLD}%
  {Composite (block) SLD element: argument 1 is a \linespec\ that can be used
   to set the direction and distance between primary terminals but not
   position.

   Argument 2 contains semicolon (;)-separated key-value body attributes:
   {\tt name={\sl{}Name}} (default {\sl Body});
   {\tt type=S|C} (default {\tt S});
   {\tt scale={\sl expr}} (body size factor, default 1.0);
   {\tt direct=L|R} (default {\tt L}) direction of the tertiary
     circle and terminal relative to the drawing direction;
   {\tt body={\sl circle attributes}}.

   Argument 3 is colon (:)-separated sequence of up to three breaker
   attribute specifications for the input, output, and teriary breaker
   in order.  A null or blank means no breaker, {\tt tt\_breaker}
   specifications otherwise. Default breaker names are {\sl BrI}
   and {\sl BrO} as for
   {\tt sl\_transformer,} and {\sl Br} for the third breaker. 

   Argument 4 is colon (:)-separated sequence of up to three symbol
   specifications for the input, output, and teriary circle
   in order.  A null or blank means no symbol;
   {\tt Y} for a Y-symbol;
   {\tt Delta} for a $\Delta$ symbol;
   otherwise, other customization commands expanded in a {\tt \lbr\rbr} pair.
   \seesect{SingleLine:}}%
%
\macrodef{sl\_transformer}{sl_transformer}{({\sl linespec, keys,
    input breaker keys, output breaker keys,
    input circle inner object, output circle inner object})}%
  {SLD}%
  {Two-terminal SLD element: argument 1 is a \linespec\ as for ordinary
   two-terminal elements.

   Argument 2 contains semicolon (;)-separated key-value body attributes:
   {\tt name={\sl{}Name}} (default {\sl Body});
   {\tt scale={\sl expr}} (body size factor, default 1.0);
   {\tt type=I|S|A[R]} (default {\tt I}).

   Additional type {\tt I} keys are
   {\tt cycles={\sl{}integer}} (default 4);
   {\tt core=A|M[$n$]|P[$n$]|K[$n$]}, $n$={\sl integer} (default 2 lines).

   Additional type {\tt S} keys are
   {\tt body={\sl circle pic attributes}} e.g., {\tt shaded "{\sl color}"}.

   Type {\tt A} keys are
   {\tt body={\sl circle pic attributes}}.  Type {\tt AR} means right
   orientation.

   Argument 3 is null for no breaker in the input lead, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   key-value pairs as above defining breaker attributes
   except that the default breaker name is {\sl BrI}.

   Argument 4 defines the breaker in the output lead as for argument 3
   except that the default breaker name is {\sl BrO}.

   Argumentss 5 and 6 for the input and output circles respectively are:
   {\tt Y} for a Y-symbol;
   {\tt YN} for a Y-symbol with ground;
   {\tt Delta} for a $\Delta$ symbol;
   otherwise, other customization commands expanded in a {\tt \lbr\rbr} pair.
   \seesect{SingleLine:}}%
%
\macrodef{sl\_ttbox}{sl_ttbox}{({\sl linespec, keys, input breaker keys,
    output breaker keys})}%
  {SLD}%
  {Two-terminal SLD element: argument 1 is a \linespec\ as for ordinary
   two-terminal elements.

   Argument 2 contains semicolon (;)-separated key-value body attributes:
   {\tt name={\sl{}Name}} (default {\sl Body});
   {\tt lgth={\sl{}expr}};
   {\tt wdth={\sl{}expr}};
   {\tt text="{\sl{}text}"};
   {\tt box={\sl{}box pic attributes}};
   {\tt supp={\sl{}additional {\tt rotbox} commands}}.

   Argument 3 is null for no breaker in the input lead, {\tt C} for a default
   closed breaker, {\tt O} for an open breaker, {\tt X,} {\tt /,} or \bsl\ for
   these marks, or
   key-value pairs as above defining breaker attributes
   except that the default breaker name is {\sl BrI}.

   Argument 4 defines the breaker in the output lead as for argument 3
   except that the default breaker name is {\sl BrO}.
   \label{sl_ttbox}
   \seesect{SingleLine:}}%
\macrodef{s\_name}{s_name}{}%
  {gen}%
  {the value of the last {\tt s\_init} argument
    \seesect{Interaction:}}%
\macrodef{sourcerad\_}{sourcerad_}{}%
  {cct}%
  {default source radius}%
\macrodef{slantbox}{slantbox}{%
  ({\sl wid, height, x offset, y offset,  attributes})}%
  {dpictools}%
  {$\;\;$ Trapezoid formed from a box with top corners displaced right by
    $x$ offset and right corners displaced up by $y$ offset.}%
\macrodef{source}{source}{(\linespec, {\sl char or chars}, {\sl diameter},R,
  {\sl body attributes, body name})}%
  {cct}%
  {Source; arg2 blank or:\\
               {\tt AC}: AC source;\\
               {\tt B}: bulb;\\
               {\tt F}: fluorescent;\\
               {\tt G}: generator;\\
               {\tt H}: step function;\\
               {\tt I}: current source;\\
               {\tt i}: alternate current source;\\
               {\tt ii}: double arrow current source;\\
               {\tt ti}: truncated-bar alternate current source;\\
               {\tt dci}: DC current source;\\
               {\tt L}: lamp;\\
               {\tt N}: neon;\\
               {\tt NA}: neon 2;\\
               {\tt NB}: neon 3;\\
               {\tt P}: pulse;\\
               {\tt Q}: charge;\\
               {\tt R}: ramp;
               {\tt S}: sinusoid;\\
               {\tt SC}: quarter arc, {\tt SCr} right orientation;\\
               {\tt SE}: arc, {\tt SEr} right orientation;\\
               {\tt T}: triangle;\\
               {\tt U}: square-wave;\\
               {\tt V}: voltage source;\\
               {\tt v}: alternate voltage source;\\
               {\tt tv}: truncated-bar alternate voltage source;\\
               {\tt dcv}: DC voltage source;\\
               {\tt X}: interior X;\\
               other: custom interior label or waveform;\\
        arg 4: R: reversed polarity;\\
        arg 5 modifies the circle (body) with e.g., color or fill;\\
        arg 6 names the body {\tt [ ]} block
   \seesect{Twoterminal:}}%
\macrodef{speaker}{speaker}{( U|D|L|R|{\sl degrees},{\sl size},H,attributes)}%
  {cct}%
  {speaker, {\sl In1} to {\sl In7} defined; {\tt H}: horn
   \seesect{Composite:}}%
\macrodef{sprod3}{sprod3}{({\sl scalar, vec1, vec2})}%
  {dpictools}%
  {$\;\;$ Multiplied vector by scalar arg1: {\sl vec2 = vec1 * arg1}.}%
\macrodef{sprod3D}{sprod3D}{(a,x,y,z)}%
  {3D} {scalar product of triple x,y,z by arg1}%
\macrodef{sp\_}{sp_}{}%
  {gen}%
  {evaluates to medium space for gpic strings}%
\macrodef{sqrta}{sqrta}{({\sl arg})}%
  {gen}%
  {square root of the absolute value of {\sl arg}; i.e.,
   {\tt sqrt(abs({\sl arg}))}}%
\macrodef{SQUID}{SQUID}{({\sl n, diameter, initial angle}, {\tt ccw|cw})}%
  {cct}%
  {Superconducting quantum interface device
   with {\sl }n junctions labeled {\tt J1, ... J}{\sl n} placed around
   a circle with initial angle -90 deg (by default) with respect to the
   current drawing direction. The default diameter is {\tt dimen\_} }%
\macrodef{s\_}{s_}{}%
  {gen}%
  {.s with respect to current direction}%
\macrodef{stackargs\_}{stackargs}{(`{\sl stackname}',{\sl args})}%
  {gen}%
  {Stack arg 2, arg 3, ... onto the named stack up to a blank arg}%
\macrodef{stackcopy\_}{stackcopy_}{(`{\sl name 1}',`{\sl name 2}')}%
  {gen}%
  {Copy stack 1 into stack 2, preserving the order of pushed elements}%
\macrodef{stackdo\_}{stackdo}{(`{\sl stackname}',{\sl commands})}%
  {gen}%
  {Empty the stack to the first blank entry, performing arg 2}%
\macrodef{stackexec\_}{stackexec_}{(`{\sl name 1}',`{\sl name 2}',%
 {\sl commands})}%
  {gen}%
  {Copy stack 1 into stack 2, performing arg3 for each nonblank
  entry}%
\macrodef{stackprint\_}{stackprint_}{(`{\sl stack name}')}%
  {gen}%
  {Print the contents of the stack to the terminal}%
%\macrodef{stackpromote\_}{stackpromote_}{({\sl prefix},% 
% `{\sl stack name}',{\sl In name})}%
%  {gen}%
%  {Define locations {\tt In1} or {\sl In name }{\tt 1}, $\ldots$ corresponding %   to the locations in stack {\sl stack name}, as created by the
%   {\tt AutoGate} and {\tt Autologic} macros.  Each location is prefixed
%   by argument 1 ``.''}%
\macrodef{stackreverse\_}{stackreverse_}{(`{\sl stack name}')}%
  {gen}%
  {Reverse the order of elements in a stack, preserving the name}%
\macrodef{stacksplit\_}{stacksplit_}{(`{\sl stack name}',{\sl string},{\sl
   separator})}%
  {gen}%
  {Stack the fields of {\sl string} left to right separated
  by nonblank
    {\sl separator} (default .).  White space preceding the fields
    is ignored.}%
\macrodef{sum3}{sum3}{({\sl vec1, vec2, vec3})}%
  {dpictools}%
  {$\;\;$ The 3-vector sum
    $\hbox{\sl vec3} = \hbox{\sl vec1} + \hbox{\sl vec2}$.}%
\macrodef{sum3D}{sum3D}{({\sl x1,y1,z1,x2,y2,z2})}%
  {3D} {sum of two triples}%
\macrodef{sum\_}{sum_}{({\sl a},{\sl b})}%
  {gen}%
  {binary sum}%
\macrodef{sus}{sus}{({\sl linespec, chars, label})}%
  {cct}%
  {Wrapper to place an SUS thyristor as a two-terminal element with
   {\tt [ ]} block label given by the third argument
    \seesect{Semiconductors:}}%
\macrodef{svec\_}{svec_}{({\sl x},{\sl y})}%
  {log}%
  {scaled and rotated grid coordinate vector}%
\macrodef{s\_wd}{s_wd}{({\sl name},{\sl default})}%
  {gen}%
  {width of the most recent (or named) {\tt s\_box}%
    \seesect{Interaction:}}%
\macrodef{switch}{switch}{(\linespec,L|R,[C|O][D],[B|D])}%
  {cct}%
  {SPST switch (wrapper for bswitch, lswitch, and dswitch),
    arg2: {\tt R}: right orientation (default {\tt L} for left);\\
     if arg4=blank (knife switch): arg3 = {\tt [O|C][D][A]},
       {\tt O}: opening, {\tt C}: closing, {\tt D}:dots,
       {\tt A}: blade arrowhead;\\
     if arg4=B (button switch): arg3 = 
       {\tt O|C}: {\tt O}: normally open, {\tt C}: normally closed;\\
     if arg4={\tt D}: arg3 = same as for dswitch \seesect{Twoterminal:}}%
\macrodef{sw\_}{sw_}{}%
  {gen}%
  {.sw with respect to current direction}%

\Letter{T}%

\macrodef{tapped}{tapped}{(`{\sl two-terminal element}',
  [{\sl arrowhd} | type={\sl arrowhd};name={\sl Name}],
    {\sl fraction, length, fraction, length,} $\cdots$)}%
  {cct}%
  {Draw the two-terminal element with taps in a [ ] block (see
  {\tt addtaps}).
   {\sl arrowhd} = blank or one of {\tt . - <- -> <->}.  Each fraction
   determines the position along the element body of the tap.  A negative
   length draws the tap to the right of the current direction; positive
   length to the left.  Tap names are Tap1, Tap2, $\cdots$ by default
   or Name1, Name2, $\cdots$ if specified.  Internal block names are
   {\tt .Start, .End,} and {.C} corresponding to the drawn element,
   and the tap names \seesect{Composite:} }%
\macrodef{ta\_xy}{ta_xy}{({\sl x, y})}%
  {cct}%
  {macro-internal coordinates adjusted for {\tt L|R}}%
\macrodef{tbox}{tbox}{({\sl text,wid,ht},<|>|<>,{\sl attributes})}%
  {cct}%
  {Pointed terminal box. The {\sl text} is placed at the rectangular
  center
   in math mode unless the text begins with {\tt "} or {\tt sprintf} in
   which case the arument is used literally.  Arg 4 determines whether
   the point is forward, backward, or both with respect to the current
   drawing direction.
    \seesect{Composite:}}%
\macrodef{tconn}{tconn}{({\sl linespec, chars}|{\sl keys}, {\sl wid})}%
  {cct}%
  {Terminal connector drawn on a linespec, with head enclosed in a {\tt []}%
   block.  The permissible {\sl chars} are:
   {\tt > | >{}> | < | <{}< | A | AA | M | O | OF}.
   Type {\tt O} draws a node (circle); {\tt OF} a filled circle.
   Type {\tt M} is a black bar; {\tt A} is an open arc end; type {\tt AA}
   a double open arc.  Type {\tt >} (the default) is an arrow-like output
   connector; {\tt <} and {\tt <<} input connectors.  Arg 3 is arrowhead
   width or circle diameter when key-value pairs are not used.
   If keys are specified, they are {\tt type=}{\sl chars} as previously;
   {\tt wdth=}{\sl expr}; {\tt lgth=}{\sl expr}; {\tt sep=}{\sl expr};
   {\tt head=}{\sl attributes except} {\tt lgth, wdth.}
   The key {\tt sep=} is the double-head separation
    \seesect{Composite:}}%
\macrodef{testexpr}{testexpr}{({\sl variable, expr1, expr2, \ldots})}%
  {dpictools}%
  {$\;\;$ Set the variable given by arg1 to the index of the first true
  alternative in a sequence of logical expressions, e.g.,
  {\tt testexpr(i, 1>2, 1<2 )} sets {\sl i} to 2. The variable is set to 0
   if no test is true.}%
\macrodef{tgate}{tgate}{({\sl linespec,} [B][R|L])}%
  {cct}%
  {transmission gate, {\tt B=} ebox type; {\tt L=} oriented left
    \seesect{Semiconductors:}}%
\macrodef{thermocouple}{thermocouple}{({\sl linespec, wid, ht,} L|R [T])}%
  {cct}%
  { Thermocouple drawn to the left (by default) of the
    {\sl linespec} line.  A {\tt T} argument truncates the leads so
    only the two branches appear.  {\tt R=} right orientation.
    \seesect{Twoterminal:}}%
\macrodef{thicklines\_}{thicklines_}{({\sl number})}%
  {gen}%
  {set line thickness in points}%
\macrodef{thinlines\_}{thinlines_}{({\sl number})}%
  {gen}%
  {set line thickness in points}%
\macrodef{threeD\_init}{threeD_init}{}%
  {3D} {initialize 3D transformations (reads {\tt lib3D.m4})}%
\macrodef{thyristor}{thyristor}{(\linespec,%
 {\tt [SCR|SCS|SUS|SBS|IEC][{\sl chars}]})}%
  {cct}%
  {Composite thyristor element in {\tt []}block, types:\\
                     {\tt SCR}: silicon controlled rectifier (default),\\
                     {\tt SCS}: silicon controlled switch,\\
                     {\tt SUS}: silicon unilateral switch,\\
                     {\tt SBS}: silicon bilateral switch,\\
                     {\tt IEC}: type IEC.\\
   {\sl Chars} to modify or define the element:\\
                     {\tt K}: open arrowheads,\\
                     {\tt A}: arrowhead,\\
                     {\tt F}: half arrowhead,\\
                     {\tt B}: bidirectional diode,\\
                     {\tt E}: adds envelope,\\
                     {\tt H}: perpendicular gate (endpoint {\sl G}),\\
                     {\tt N}: anode gate (endpoint {\sl Ga}),\\
                     {\tt U}: centre line in diodes,\\
                     {\tt V}: perpendicular gate across arrowhead centre,\\
                     {\tt R}: right orientation,\\
                     {\tt E}: envelope
    \seesect{Semiconductors:}}%
\macrodef{thyristor\_t}{thyristor_t}{({\sl linespec, chars, label})}%
  {cct}%
  {Wrapper to place a thyristor as a two-terminal element with
   {\tt [ ]} block label given by the third argument
    \seesect{Semiconductors:}}%
\macrodef{tikznode}{tikznode}{({\sl \Tikz node name, position}) }%
  {pgf}%
  {insert \Tikz code to define a zero-size \Tikz node at {\sl location}%
    (default {\tt Here}) to assist with inclusion of \pic code output
    in \Tikz diagrams.  This macro must be invoked in the outermost
    \pic scope.  \seesect{Tikzwithpic:}}%
\macrodef{tline}{tline}{(\linespec,{\sl wid},{\sl ht}) }%
  {cct}%
  {transmission line, manhattan direction\seesect{Twoterminal:}}%
\macrodef{ToPos}{ToPos}{({\sl position}, U|D|L|R|{\sl degrees}, {\sl length}) }%
  {gen}%
  {Evaluates to {\tt from {\sl position} - Rect\_({\sl length, angle}) to
   {\sl position}} from the polar-coordinate data in the arguments }%
\macrodef{transformer}{transformer}{(\linespec,L|R,{\sl np},%
[A|P][W|L][D1|D2|D12|D21],{\sl ns})}%
  {cct}%
  {2-winding transformer or choke with terminals {\sl P1, P2, TP, S1, S2, TS}:\\
    arg2: {\tt L}: left, {\tt R}: right,\\
    arg3: np primary arcs,\\
    arg5: ns secondary arcs,\\
    arg4:
    {\tt A}: air core,\\
    {\tt P}: powder (dashed) core,\\
    {\tt W}: wide windings,\\
    {\tt L}: looped windings,\\
    {\tt D1}: phase dots at {\sl P1} and {\sl S1} end;\\
    {\tt D2}: at {\sl P2} and {\sl S2} end;\\
    {\tt D12}: at {\sl P1} and {\sl S2} end;\\
    {\tt D21} at {\sl P2} and {\sl S1} end
   \seesect{Composite:}}%
\macrodef{tr\_xy\_init}{tr_xy_init}{({\sl origin, unit size, sign })}%
  {cct}%
  {initialize {\tt tr\_xy}}%
\macrodef{tr\_xy}{tr_xy}{({\sl x, y})}%
  {cct}%
  {relative macro internal coordinates adjusted for {\tt L|R}}%
\macrodef{tstrip}{tstrip}{(R|L|U|D|{\sl degrees, nterms, chars})}%
  {cct}%
  {terminal strip, chars:
   I (invisible terminals), C (default circle terminals), D (dot terminals),
   O (omitted separator lines), {\tt wid=}value{\tt ;} total strip width,
   {\tt ht=}value{\tt ;} strip height, {\tt box={\sl shaded etc.};}
    \seesect{Composite:}}%
\macrodef{ttmotor}{ttmotor}{({\sl linespec, string, diameter, brushwid,
brushht})}%
  {cct}%
  {motor with label\seesect{Twoterminal:}}%
\macrodef{twopi\_}{twopi_}{}%
  {gen}%
  {$2\pi$}%

\Letter{U}%

\macrodef{ujt}{ujt}{(\linespec,R,P,E)}%
  {cct}%
  {unijunction transistor, right, P-channel, envelope
    \seesect{Semiconductors:}}%
\macrodef{unit3D}{unit3D}{(x,y,z)}%
  {3D} {unit triple in the direction of triple x,y,z}%
\macrodef{up\_\_}{up__}{}%
  {gen}%
  {up with respect to current direction}%
\macrodef{up\_}{up_}{}%
  {gen}%
  {set current direction up \seesect{Placing:}}%

\Letter{V}%

\macrodef{variable}{variable}{(`{\sl element}', {\sl chars}, [+|-]{\sl angle},
   {\sl length}, at position)}%
% {\tt [A|P|L|[u]N|[u]NN][C|S]},
  {cct}%
  {Overlaid arrow or line to indicate variable 2-terminal element:
    The {\sl chars} are\\
    {\tt A}: arrow,\\
    {\tt P}: preset,\\
    {\tt L}: linear,\\
    {\tt N}:  symmetric nonlinear,\\
    {\tt C}: continuous,\\
    {\tt S}: setpwise;\\
    {\tt u} changes the nonlinearity direction.  The angle is absolute
    but preceding it with a sign makes the angle (often -30 or -45)
    relative to the element drawing direction.\\
    If arg5 is blank the symbol is placed over the last {\tt []} block
   \seesect{Twoterminal:}}%
\macrodef{Vcoords\_}{Vcoords_}{({\sl position})}%
  {gen}%
  {The $x, y$ coordinate pair of the position}%
\macrodef{Vdiff\_}{Vdiff_}{({\sl position},{\sl position})}%
  {gen}%
  {{\tt Vdiff\_(A,B)} evaluates to {\tt A-(B)} with dpic, {\tt A-(B.x,B.y)}
   with gpic}%
\macrodef{vec\_}{vec_}{({\sl x},{\sl y})}%
  {gen}%
  {position rotated with respect to current direction}%
\macrodef{vec\_r}{vec_r}{({\sl x},{\sl y})}%
  {gen}%
  {Robust position rotated with respect to current direction for use in
   dpic loops}%
\macrodef{vec3}{vec3}{({\sl vector})}%
  {dpictools}%
  {$\;\;$ Expands to the threee components of the vector argument separated
    by commas.}%
\macrodef{View3D}{View3D}{}%
  {3D} {The view vector (triple) defined by {\tt setview({\sl azimuth,
   elevation, rotation})}. The {\tt project} macro projects onto the plane
   through {\tt (0,0)} and orthogonal to this vector.}%
\macrodef{vlength}{vlength}{({\sl x},{\sl y})}%
  {gen}%
  {vector length $\sqrt{x^2+y^2}$}%
\macrodef{vperp}{vperp}{({\sl linear object})}%
  {gen}%
  {unit-vector pair CCW-perpendicular to linear object}%
\macrodef{Vperp}{Vperp}{({\sl position name}, {\sl position name})}%
  {gen}%
  {unit-vector pair CCW-perpendicular to line joining two named positions}%
\macrodef{vrot\_}{vrot_}{({\sl x},{\sl y},{\sl xcosine},{\sl ycosine})}%
  {gen}%
  {rotation operator}%
\macrodef{vscal\_}{vscal_}{({\sl number},{\sl x},{\sl y})}%
  {gen}%
  {vector scale operator}%
\macrodef{Vsprod\_}{Vsprod_}{({\sl position}, {\sl expression})}%
  {gen}%
  {The vector in arg 1 multiplied by the scalar in arg 2}%
\macrodef{Vsum\_}{Vsum_}{({\sl position},{\sl position})}%
  {gen}%
  {{\tt Vsum\_(A,B)} evaluates to {\tt A+B} with dpic, {\tt A+(B.x,B.y)}
   with gpic}%

\Letter{W}%

\macrodef{while\_}{while_}{(`{\sl test}',`{\sl actions}')}%
  {gen}%
  {Integer m4 while loop}%
\macrodef{wid\_}{wid_}{}%
  {gen}%
  {width with respect to current direction}%
\macrodef{winding}{winding}{(L|R, {\sl winding diam, pitch, nturns, core wid,
   {\tt "}core color{\tt "}})}%
  {cct}%
  {core winding drawn in the current direction; {\tt R}: right-handed
   The complete spline is drawn in the current drawing direction, then
   parts of it are overwritten with the background core color (default white).
   Arg 1 contains R for right-handed winding.
   \seesect{Composite:}}%
\macrodef{w\_}{w_}{}%
  {gen}%
  {.w with respect to current direction}%

\Letter{X}%

\macrodef{XOR\_gate}{XOR_gate}{({\sl n},N)}%
  {log}%
  {`xor' gate, 2 or {\sl n\/} inputs; {\tt N}: negated input.
   Otherwise, arg1 can be a sequence of letters {\tt P|N} to define
   normal or negated inputs.
   The default output conforms to current ANSI standard by drawing short
   lines from the inputs to the gate main body. Original behaviour to
   omit them can be set by {\tt define(`XOR\_off',-1)} either globally
   or for individual gates.
    \seesect{Logicgates:}}%
\macrodef{XOR\_off}{XOR_off}{}%
  {log}%
  {XOR and NXOR offset parameter of the input face, equal to 1 to conform
   to current ANSI standard by drawing short lines from the inputs to
   the gate main body.  Original behaviour to omit them can be set by
   {\tt define(`XOR\_off',-1)} either globally or for individual gates.}
\macrodef{xtal}{xtal}{(\linespec,{\sl keys})}%
  {cct}%
  {Quartz crystal. The {\sl keys} are
     {\tt type=N} (default) or {\tt type=R} (round);\\
            type {\tt N} keys:\\
              {\tt lgth=}{\sl expr} (body length);\\
              {\tt wdth=}{\sl expr} (body width);\\
              {\tt bxwd=}{\sl expr} (body inner box width);\\
              {\tt box=} box attributes ({\tt shaded} $\ldots$);\\
            type {\tt R} keys:\\
              {\tt outerdiam=}{\sl expr};\\
              {\tt innerdiam=}{\sl expr};\\
              {\tt outer=} outer circle attributes ({\tt dotted} $\ldots$);\\
              {\tt inner=} inner circle attributes ({\tt shaded} $\ldots$)%
\seesect{Twoterminal:}}%
\macrodef{xtract}{xtract}{({\sl string, substr1, substr2, $\ldots$})}%
  {gen}%
  {returns substrings if present}%

\Letter{Y}%

\macrodef{Ysymbol}{Ysymbol}{(at {\sl position, keys,}
    U|D|L|R|{\sl degrees, attributes}) (default {\tt U} for up)}%
  {cct}%
  {Y symbol for power-system diagrams.
   {\sl keys:} {\tt size={\sl expression};\\
   type=G[L]} (grounded; {\tt L} puts the ground on the left).\\
   Arg4 is the attributes of the drawn line object,
   e.g., {\tt outlined "red"}}%

\Letter{Z}%

\macrodef{zabs}{zabs}{({\sl complex value})}%
  {dpictools}%
  {$\;\;$ Absolute value of complex value $\sqrt{(val.x^2+val.y^2}$}%
\macrodef{zarg}{zarg}{({\sl complex value})}%
  {dpictools}%
  {$\;\;$ Angle of complex value $\hbox{atan2}(val.y, val.x)$}%
\macrodef{Zcos}{Zcos}{({\sl complex value})}%
  {dpictools}%
  {$\;\;$ Complex cosine
    $(\cos(val.x)*\cosh(val.y), -\sin(val.x)*\sinh(val.y))$}%
\macrodef{Zdiff}{Zdiff}{({\sl complex value, complex value})}%
  {dpictools}%
  {$\;\;$ Complex subtraction $(val1.x-val2.x, val1.y-val2.y)$}%
\macrodef{Zexp}{Zexp}{({\sl complex value})}%
  {dpictools}%
  {$\;\;$ Complex exponential $((\cos(val.y), \sin(val.y))*e^{val.x})$}%
\macrodef{Zinv}{Zinv}{({\sl complex value})}%
  {dpictools}%
  {$\;\;$ Complex inverse $((val.x, -val.y)/\hbox{zabs}(val))$}%
\macrodef{Zprod}{Zprod}{({\sl complex value, complex value})}%
  {dpictools}%
  {$\;\;$ Complex multiplication
   $(val1.x*val2.x-val1.y*val2.y, val1.y*val2.x+val1.x*val2.y)$}%
\macrodef{Zsin}{Zsin}{({\sl complex value})}%
  {dpictools}%
  {$\;\;$ Complex sine
   $(\sin(val.x)*\cosh(val.y), \cos(val.x)*\sinh(val.y))$}%
\macrodef{Zsum}{Zsum}{({\sl complex value, complex value})}%
  {dpictools}%
  {$\;\;$ Complex addition $(val1.x+val2.x, val1.y+val2.y)$}%

%  \end{tabbing}%
