Certification Problem

Input (TPDB TRS_Relative/Relative_05/rt1-2)

The relative rewrite relation R/S is considered where R is the following TRS

f(x) x (1)
g(x) x (2)

and S is the following TRS.

f(x) g(x) (3)
g(x) f(x) (4)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by ttt2 @ termCOMP 2023)

1 Rule Removal

Using the linear polynomial interpretation over (5 x 5)-matrices with strict dimension 1 over the naturals
[g(x1)] =
1 0 0 0 0
0 1 0 0 0
0 0 1 0 0
0 0 0 1 0
0 0 0 0 1
· x1 +
1 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
[f(x1)] =
1 0 0 0 0
0 1 0 0 0
0 0 1 0 0
0 0 0 1 0
0 0 0 0 1
· x1 +
1 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
all of the following rules can be deleted.
f(x) x (1)
g(x) x (2)

1.1 R is empty

There are no rules in the TRS. Hence, it is terminating.