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