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