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