On Fri, Jun 01, 2001 at 12:41:05PM -0400, Ken Shan wrote:
On 2001-06-01T08:41:34-0700, Andrew Moran wrote:
There's also \llbracket and \rrbracket, from stmaryrd. They look better than the negative space hack, IMHO (now all I need is for Alan Jeffrey to write in and say that \{ll,rr}bracket are implemented with the negative space hack :-)
Heh. Actually they're not (and cannot, because they are extensible delimiters -- useful for typesetting the denotation of multiple-line programs!).
Here's a negative space hack that gives extensible brackets: write \Sem{expr} to wrap an expression. (Doubtless someone who knows TeX could do better.) \newsavebox{\sembox} \newlength{\semwidth} \newlength{\boxwidth} \newcommand{\Sem}[1]{% \sbox{\sembox}{\ensuremath{#1}}% \settowidth{\semwidth}{\usebox{\sembox}}% \sbox{\sembox}{\ensuremath{\left[\usebox{\sembox}\right]}}% \settowidth{\boxwidth}{\usebox{\sembox}}% \addtolength{\boxwidth}{-\semwidth}% \left[\hspace{-0.3\boxwidth}% \usebox{\sembox}% \hspace{-0.3\boxwidth}\right]% }