Get the then field from a stmt-if.
This is an ordinary field accessor created by fty::defprod.
Function:
(defun stmt-if->then$inline (x) (declare (xargs :guard (stmtp x))) (declare (xargs :guard (equal (stmt-kind x) :if))) (let ((__function__ 'stmt-if->then)) (declare (ignorable __function__)) (mbe :logic (b* ((x (and (equal (stmt-kind x) :if) x))) (stmt-fix (std::da-nth 1 (cdr x)))) :exec (std::da-nth 1 (cdr x)))))
Theorem:
(defthm stmtp-of-stmt-if->then (b* ((then (stmt-if->then$inline x))) (stmtp then)) :rule-classes :rewrite)
Theorem:
(defthm stmt-if->then$inline-of-stmt-fix-x (equal (stmt-if->then$inline (stmt-fix x)) (stmt-if->then$inline x)))
Theorem:
(defthm stmt-if->then$inline-stmt-equiv-congruence-on-x (implies (stmt-equiv x x-equiv) (equal (stmt-if->then$inline x) (stmt-if->then$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm stmt-if->then-when-wrong-kind (implies (not (equal (stmt-kind x) :if)) (equal (stmt-if->then x) (stmt-fix nil))))