Basic equivalence relation for comb-transform structures.
Function:
(defun comb-transform-equiv$inline (x acl2::y) (declare (xargs :guard (and (comb-transform-p x) (comb-transform-p acl2::y)))) (equal (comb-transform-fix x) (comb-transform-fix acl2::y)))
Theorem:
(defthm comb-transform-equiv-is-an-equivalence (and (booleanp (comb-transform-equiv x y)) (comb-transform-equiv x x) (implies (comb-transform-equiv x y) (comb-transform-equiv y x)) (implies (and (comb-transform-equiv x y) (comb-transform-equiv y z)) (comb-transform-equiv x z))) :rule-classes (:equivalence))
Theorem:
(defthm comb-transform-equiv-implies-equal-comb-transform-fix-1 (implies (comb-transform-equiv x x-equiv) (equal (comb-transform-fix x) (comb-transform-fix x-equiv))) :rule-classes (:congruence))
Theorem:
(defthm comb-transform-fix-under-comb-transform-equiv (comb-transform-equiv (comb-transform-fix x) x) :rule-classes (:rewrite :rewrite-quoted-constant))
Theorem:
(defthm equal-of-comb-transform-fix-1-forward-to-comb-transform-equiv (implies (equal (comb-transform-fix x) acl2::y) (comb-transform-equiv x acl2::y)) :rule-classes :forward-chaining)
Theorem:
(defthm equal-of-comb-transform-fix-2-forward-to-comb-transform-equiv (implies (equal x (comb-transform-fix acl2::y)) (comb-transform-equiv x acl2::y)) :rule-classes :forward-chaining)
Theorem:
(defthm comb-transform-equiv-of-comb-transform-fix-1-forward (implies (comb-transform-equiv (comb-transform-fix x) acl2::y) (comb-transform-equiv x acl2::y)) :rule-classes :forward-chaining)
Theorem:
(defthm comb-transform-equiv-of-comb-transform-fix-2-forward (implies (comb-transform-equiv x (comb-transform-fix acl2::y)) (comb-transform-equiv x acl2::y)) :rule-classes :forward-chaining)