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