A boolean expression evaluator and a switch command
Description
The \boolexpr macro evaluates boolean expressions in a purely
expandable way. \boolexpr{ A \OR B \AND C } expands to 0 if the
logical expression is TRUE. A, B, C may be: numeric expressions
such as: x=y, x<>y, x>y or x<y; - boolean switches: \iftrue
0\else 1\fi; - conditionals: \ifcsname whatsit\endcsname 0\else
1\fi; - another \boolexpr: \boolexpr{ D \OR E \AND F }:
\boolexpr may be used with \ifcase: \ifcase\boolexpr{ A \OR B
\AND C } What to do if true \else What to do if false \fi The
\switch command (which is also expandable) has the form:
\switch \case{<boolean expression>} ... \case{<boolean
expression>} ... ... \otherwise ... \endswitch
