Major Section: BREAK-REWRITE Example: (brr@ :target) ; the term
being rewritten (brr@ :unify-subst) ; the unifying
substitutionwhere General Form: (brr@ :symbol) :symbolis one of
the following keywords. Those marked with *probably require an
implementor's knowledge of the system to use effectively. They
are supported but not well documented. More is said on this
topic following the table. :symbol (brr@ :symbol) -------
---------------------In general :target the term to be
rewritten. This term is an instantiation of the left-hand side
of the conclusion of the rewrite-rule being broken. This term is
in translated form! Thus, if you are expecting (equal x nil) --
and your expectation is almost right -- you will see (equal x
'nil); similarly, instead of (cadr a) you will see (car (cdr
a)). In translated forms, all constants are quoted (even nil, t,
strings and numbers) and all macros are expanded. :unify-subst
the substitution that, when applied to :target, produces the
left-hand side of the rule being broken. T