Some theorems about the library function nat-list-fix.
Theorem:
(defthm cdr-of-nat-list-fix (equal (cdr (nat-list-fix x)) (nat-list-fix (cdr x))))
Theorem:
(defthm car-of-nat-list-fix-when-consp (implies (consp x) (equal (car (nat-list-fix x)) (nfix (car x)))))
Theorem:
(defthm car-of-nat-list-fix-iff-consp (iff (car (nat-list-fix x)) (consp x)))
Theorem:
(defthm rev-of-nat-list-fix (equal (rev (nat-list-fix x)) (nat-list-fix (rev x))))
Theorem:
(defthm nat-list-fix-of-true-list-fix (equal (nat-list-fix (true-list-fix x)) (nat-list-fix x)))