Recognizer for proposal-option structures.
(proposal-optionp x) → *
Function:
(defun proposal-optionp (x) (declare (xargs :guard t)) (let ((__function__ 'proposal-optionp)) (declare (ignorable __function__)) (cond ((not x) (b* nil t)) (t (b* ((fty::val x)) (proposalp fty::val))))))