Certification Problem

Input (COPS 547)

The rewrite relation of the following conditional TRS is considered.

f(x) a | xa
f(x) b | xb

Property / Task

Prove or disprove confluence.

Answer / Result

Yes.

Proof (by ConCon @ CoCo 2020)

1 Almost-orthogonal modulo infeasibility

The given (extended) properly oriented, right-stable, oriented 3-CTRS is almost-orthogonal modulo infeasibility, since all its conditional critical pairs are infeasible.