SORT

(SORT <list> <predicate> [<selector>])

The <list> is destructively sorted according to the order
determined by the <predicate>. The predicate should take two arguments,
and return true if and only if the first argument is strictly less
than the second (in some appropriate sense). 

The optional parameter <selector> is used to preprocess arguments before 
they are given to the <predicate>, like this:

(sort a p s) == (sort a (function (lambda (x y) (p (s x) (s y)))))

NOTE: the function is just the same as in Common Lisp except it has no
':key' parameter (because there are no key parameters in Intelib Lisp
at all). Instead, the function accepts optional third parameter, 
<selector>, which is interpreted the same way CL's version's :key
parameter is.