Certification Problem

Input (COPS 364)

The rewrite relation of the following conditional TRS is considered.

even(0) true
even(s(x)) true | odd(x) ≈ true
odd(s(x)) true | even(x) ≈ true

Property / Task

Prove or disprove confluence.

Answer / Result

Yes.

Proof (by ConCon @ CoCo 2020)

1 Almost-orthogonal

The given (extended) properly oriented, right-stable, oriented 3-CTRS is almost-orthogonal, since there are no conditional critical pairs.