The || command can be used in |picture| mode to draw a
quadratic bezier curve from position |(<AX>,<AY>)| to |(<CX>,<CY>)| with
control point |(<BX>,<BY>)|. The optional argument N gives the
number of points on the curve.
For example, the diagram:
is drawn with:
\begin{picture}(50,50)
\thicklines
\qbezier(0,0)(0,50)(50,50)
\qbezier[20](0,0)(50,0)(50,50)
\thinlines
\put(0,0){\line(1,1){50}}
\end{picture}
The || command is the same, except that the argument N is not
optional. It is provided for compatibility with the LATEX 2.09
|bezier| document style option.