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Sbyte2p

Recognizer for sbyte2.

Function: sbyte2p

(defun sbyte2p (x)
  (declare (xargs :guard t))
  (mbe :logic (signed-byte-p 2 x)
       :exec (and (integerp x) (<= -2 x) (< x 2))))

Theorem: booleanp-of-sbyte2p

(defthm booleanp-of-sbyte2p
  (b* ((yes/no (sbyte2p x)))
    (booleanp yes/no))
  :rule-classes :rewrite)

Theorem: sbyte2p-forward-signed-byte-p

(defthm sbyte2p-forward-signed-byte-p
  (implies (sbyte2p x)
           (signed-byte-p 2 x))
  :rule-classes :forward-chaining)

Theorem: signed-byte-p-rewrite-sbyte2p

(defthm signed-byte-p-rewrite-sbyte2p
  (equal (signed-byte-p 2 x) (sbyte2p x)))

Theorem: integerp-when-sbyte2p

(defthm integerp-when-sbyte2p
  (implies (sbyte2p x) (integerp x))
  :rule-classes :compound-recognizer)