> Another possible scheme is to return a dotted pair, in which the first
> value is t or nil, depending on the success of the match, and the
> second value is the list of sustitutions.
>
> This is the way that _Common_LISPcraft_ by Robert Wilensky does it.
Common Lisp functions often return two values in this situation: the
result (if any), and an indication of success or failure. SUBTYPEP is
a typical example.
Lawrence G. Mayka
AT&T Bell Laboratories
ยทยทยท@iexist.att.com
Standard disclaimer.