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Dec-expo-prefix

Dec-expo-prefixp

Recognizer for dec-expo-prefix structures.

Signature
(dec-expo-prefixp x) → *

Definitions and Theorems

Function: dec-expo-prefixp

(defun dec-expo-prefixp (x)
  (declare (xargs :guard t))
  (and (consp x)
       (cond ((or (atom x) (eq (car x) :locase-e))
              (and (eq (cdr x) nil) (b* nil t)))
             (t (and (eq (car x) :upcase-e)
                     (and (eq (cdr x) nil))
                     (b* nil t))))))

Theorem: consp-when-dec-expo-prefixp

(defthm consp-when-dec-expo-prefixp
  (implies (dec-expo-prefixp x) (consp x))
  :rule-classes :compound-recognizer)