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