MAYBE
LCTRS
  Theories
    Core, Ints
  Sorts
    Unit
  Signature
    fastfib: Int -> Unit
    return: Int -> Unit
    u: (Int, Int, Int, Int, Int) -> Unit
    v: (Int, Int, Int, Int, Int) -> Unit
  Rules
    v(!n, !i, !fb, !p, !q) -> return(!fb) [not(<=(!i, !n))]
    v(!n, !i, !fb, !p, !q) -> v(!n, +(!i, 1), +(!p, !q), +(!p, !q), !p) [<=(!i, !n)]
    u(!n, !i, !fb, !p, !q) -> v(!n, 2, !fb, !p, !q) [and(not(<(!n, 1)), not(!n = 1))]
    u(!n, !i, !fb, !p, !q) -> return(1) [and(not(<(!n, 1)), !n = 1)]
    u(!n, !i, !fb, !p, !q) -> return(0) [<(!n, 1)]
    fastfib(!n) -> u(!n, !rnd1, !rnd2, 1, 0)
No termination info given.

Elapsed Time:  43.26 ms