The corollary to Greenspun’s rule is that any sufficiently complicated Common Lisp program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Prolog.
It would be fun if it was "half Prolog, half Common Lisp"
I've now used both professionally. I look forward to hopefully using both in the same project. Though not holding my breath.
Well, the 'PAIP' book for sure does it, literally.