Certification Problem

Input (COPS 1091)

We consider two TRSs R and S where R contains the rules

f(a) c (1)
b c (2)
b a (3)

and S contains the following rules:

c f(c) (4)
c c (5)
f(a) b (6)
a c (7)

The underlying signature is as follows:

{a/0, b/0, c/0, f/1}

Property / Task

Prove or disprove commutation.

Answer / Result

Yes.

Proof (by ACP @ CoCo 2023)

1 Swap TRSs

The role of TRSs R and S are changed.

1.1 Development Closed

Commutation is proven since the TRSs are development closed. The joins can be performed using 5 step(s).