YES
LCTRS
  Theories
    Core, Ints
  Sorts
    Unit
  Signature
    badfib: Int -> Unit
    return: Int -> Unit
    w: (Unit, Unit) -> Unit
  Rules
    badfib(?14) -> return(1) [<=(?14, 3)]
    badfib(?15) -> w(badfib(-(?15, 1)), badfib(-(?15, 2))) [>(?15, 3)]
    w(return(?16), return(?17)) -> return(+(?16, ?17))
Confluent by Orthogonality with proof:
  no critical pairs

Elapsed Time:  44.51 ms