MAYBE
LCTRS
  Theories
    Core, Ints
  Signature
    fib: Int -> Int
    fib1: Int -> Int
    u: (Int, Int, Int, Int) -> Int
  Rules
    fib(!x) -> +(fib(-(!x, 1)), fib(-(!x, 2))) [>=(-(!x, 2), 0)]
    fib(1) -> 1
    fib(!x) -> 0 [<=(!x, 0)]
    u(!x, !i, !y, !z) -> !y [not(>=(!x, !i))]
    u(!x, !i, !y, !z) -> u(!x, +(!i, 1), !z, +(!y, !z)) [>=(!x, !i)]
    fib1(!x) -> u(!x, 1, 0, 1)
No termination info given.

Elapsed Time:  63.63 ms