[Haskell] lhs2TeX: lazy pattern "~" formatting

[kahl at cas.mcmaster.ca]

 > 
 > Does anyone have a nice way to format the "~" of a lazy pattern in
 > lhs2TeX?  I use
 > 
 >   %format ~ = "{} ^\sim "
 > 
 > but the result isn't as pretty as I'd like.  For one thing, no space
 > is inserted before the "~" after a lambda, "do", or whatever.

``Nice'' is in the eye of the beholder --- after limited fiddling,
I use:

\def\irref{{\lower0.3ex\hbox{\texttt{\bf\~{}}}}\kern-0.1em\strut}


Wolfram