YES
LCTRS
  Theories
    Core, Ints
  Defines
    isEven: ((x Int)) Bool (= (mod x 2) 0)
  Sorts
    NList
  Signature
    build: (Int, NList) -> NList
    cons: (Int, NList) -> NList
    nats: NList
    nil: NList
  Rules
    build(?10, ?11) -> build(+(?10, 1), ?11) [and(not(isEven(?10)), >=(?10, 0))]
    build(?12, ?13) -> build(+(?12, 1), cons(?12, ?13)) [and(isEven(?12), >=(?12, 0))]
    nats -> build(0, nil)
Confluent by Almost Development Closedness with proof:
  no critical pairs

Elapsed Time:  82.26 ms