YES
LCTRS
  Theories
    Core, Ints
  Signature
    double: Int -> Int
  Rules
    double(?7) -> +(2, double(-(?7, 1))) [>(?7, 0)]
    double(?8) -> 0 [<=(?8, 0)]
Confluent by Strong Closedness with proof:
  no critical pairs

Elapsed Time:  29.96 ms