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    • Rev

    Rev-theorems

    Some theorems about the library function rev.

    The theorems car-of-rev-rewrite-car-of-last and car-of-last-rewrite-car-of-rev are disabled by default. They may be useful to turn (car (rev ...)) into (car (last ...)) or vice versa. A theory invariants prevents them from being both enabled (which would cause a loop in the rewriter).

    Definitions and Theorems

    Theorem: car-of-rev-rewrite-car-of-last

    (defthm car-of-rev-rewrite-car-of-last
      (equal (car (rev x)) (car (last x))))

    Theorem: car-of-last-rewrite-car-of-rev

    (defthm car-of-last-rewrite-car-of-rev
      (equal (car (last x)) (car (rev x))))