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