Recognizer for lsuffix structures.
(lsuffixp x) → *
Function:
(defun lsuffixp (x) (declare (xargs :guard t)) (and (consp x) (cond ((or (atom x) (eq (car x) :locase-l)) (and (eq (cdr x) nil) (b* nil t))) ((eq (car x) :upcase-l) (and (eq (cdr x) nil) (b* nil t))) ((eq (car x) :locase-ll) (and (eq (cdr x) nil) (b* nil t))) (t (and (eq (car x) :upcase-ll) (and (eq (cdr x) nil)) (b* nil t))))))
Theorem:
(defthm consp-when-lsuffixp (implies (lsuffixp x) (consp x)) :rule-classes :compound-recognizer)