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