% EXOR-gate WEST
\newsavebox{\exorw}
\savebox{\exorw}(11,6){
\begin{picture}(11,6)
\bezier{60}(9,6)(4,6)(2,3)      % top section of pointed curve
\bezier{60}(9,0)(4,0)(2,3)      % bottom section of pointed curve
\bezier{40}(9,6)(7,3)(9,0)     % back curve (inner)
\bezier{40}(10,6)(8,3)(10,0)     % back curve (outer)
\put(0,3){\line(1,0){2}}         % output line
\put(11,5){\line(-1,0){1.5}}     % top input line
\put(11,1){\line(-1,0){1.5}}     % bottom input line
% NB intersection of input lines & back curve is estimated (not calculated)!
\end{picture}
}