Basic theorems about faig-eval.
Theorem:
(defthm aig-env-equiv-implies-equal-faig-eval-2 (implies (aig-env-equiv env env-equiv) (equal (faig-eval x env) (faig-eval x env-equiv))) :rule-classes (:congruence))
Theorem:
(defthm faig-eval-append-when-not-intersecting-alist-keys (implies (not (intersectp-equal (alist-keys env) (faig-vars x))) (equal (faig-eval x (append env rest)) (faig-eval x rest))))