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, !now, !next, !i, !tmp) -> return(!next) [not(<=(!i, !n))]
    v(!n, !now, !next, !i, !tmp) -> v(!n, !next, +(!next, !now), +(!i, 1), !now) [<=(!i, !n)]
    u(!n, !now, !next, !i, !tmp) -> v(!n, 1, 1, 3, !tmp) [and(not(<=(!n, 0)), not(!n = 1))]
    u(!n, !now, !next, !i, !tmp) -> return(1) [and(not(<=(!n, 0)), !n = 1)]
    u(!n, !now, !next, !i, !tmp) -> return(0) [<=(!n, 0)]
    fastfib(!n) -> u(!n, !rnd1, !rnd2, !rnd3, !rnd4)
No termination info given.

Elapsed Time:  54.60 ms