Get the fty::val field from a maybe-function-header-some.
(maybe-function-header-some->val x) → fty::val
This is an ordinary field accessor created by fty::defprod.
Function:
(defun maybe-function-header-some->val$inline (x) (declare (xargs :guard (maybe-function-headerp x))) (declare (xargs :guard x)) (let ((__function__ 'maybe-function-header-some->val)) (declare (ignorable __function__)) (mbe :logic (b* ((x (and x x))) (function-header-fix x)) :exec x)))
Theorem:
(defthm function-headerp-of-maybe-function-header-some->val (b* ((fty::val (maybe-function-header-some->val$inline x))) (function-headerp fty::val)) :rule-classes :rewrite)
Theorem:
(defthm maybe-function-header-some->val$inline-of-maybe-function-header-fix-x (equal (maybe-function-header-some->val$inline (maybe-function-header-fix x)) (maybe-function-header-some->val$inline x)))
Theorem:
(defthm maybe-function-header-some->val$inline-maybe-function-header-equiv-congruence-on-x (implies (maybe-function-header-equiv x x-equiv) (equal (maybe-function-header-some->val$inline x) (maybe-function-header-some->val$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm maybe-function-header-some->val-when-wrong-kind (implies (not x) (equal (maybe-function-header-some->val x) (function-header-fix nil))))