Additional theorems about byte.
Theorem:
(defthm bytep-forward-unsigned-byte-p (implies (bytep x) (unsigned-byte-p 8 x)) :rule-classes :forward-chaining)
Theorem:
(defthm unsigned-byte-p-rewrite-bytep (equal (unsigned-byte-p 8 x) (bytep x)))
Theorem:
(defthm natp-when-bytep (implies (bytep x) (natp x)) :rule-classes :compound-recognizer)