MAYBE
LCTRS
  Theories
    Core, Ints
  Signature
    return: Int -> Int
    sum2: (Int, Int) -> Int
    u: (Int, Int, Int, Int) -> Int
  Rules
    sum2(!m, !n) -> u(!m, !n, !m, 0)
    u(!m, !n, !i, !total) -> u(!m, !n, +(!i, 1), +(!total, !i)) [<=(!i, !n)]
    u(!m, !n, !i, !total) -> return(!total) [not(<=(!i, !n))]
No termination info given.

Elapsed Time:  48.49 ms