One can develop rule-based term rewriting systems in Lisp (and integrate them) and there are some, but itself is not defined or implemented as such. That can b

One can develop rule-based term rewriting systems in Lisp (and integrate them) and there are some, but itself is not defined or implemented as such. That can be seen by the clumsy implementation of lexical scope (renaming vars, etc.) in Mathematica or the limited compilation of the Mathematica language.