Recognizer for sbyte3.
(sbyte3p x) → yes/no
Function:
(defun sbyte3p (x) (declare (xargs :guard t)) (mbe :logic (signed-byte-p 3 x) :exec (and (integerp x) (<= -4 x) (< x 4))))
Theorem:
(defthm booleanp-of-sbyte3p (b* ((yes/no (sbyte3p x))) (booleanp yes/no)) :rule-classes :rewrite)
Theorem:
(defthm sbyte3p-forward-signed-byte-p (implies (sbyte3p x) (signed-byte-p 3 x)) :rule-classes :forward-chaining)
Theorem:
(defthm signed-byte-p-rewrite-sbyte3p (equal (signed-byte-p 3 x) (sbyte3p x)))
Theorem:
(defthm integerp-when-sbyte3p (implies (sbyte3p x) (integerp x)) :rule-classes :compound-recognizer)