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