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