Recognizer for maybe-type-sum structures.
(maybe-type-sump x) → *
Function:
(defun maybe-type-sump (x) (declare (xargs :guard t)) (let ((__function__ 'maybe-type-sump)) (declare (ignorable __function__)) (cond ((not x) (b* nil t)) (t (b* ((fty::val x)) (type-sump fty::val))))))