Certification Problem

Input (TPDB TRS_Standard/Strategy_removed_AG01/#4.20)

The rewrite relation of the following TRS is considered.

f(f(x)) f(x) (1)
g(0) g(f(0)) (2)

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
[0] =
0 0 0 0 0
0 0 0 0 0
1 0 0 0 0
1 0 0 0 0
0 0 0 0 0
[f(x1)] =
1 0 0 0 0
0 0 0 1 1
0 0 0 0 0
0 0 0 0 0
0 0 0 1 1
· x1 +
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
1 0 0 0 0
0 0 0 0 0
[g(x1)] =
1 0 1 0 0
0 0 0 0 0
0 0 0 1 0
0 0 0 0 0
0 0 0 0 0
· x1 +
0 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.
g(0) g(f(0)) (2)

1.1 Rule Removal

Using the Weighted Path Order with the following precedence and status
prec(f) = 0 status(f) = [1] list-extension(f) = Lex
and the following Max-polynomial interpretation
[f(x1)] = 2 + 1 · x1
all of the following rules can be deleted.
f(f(x)) f(x) (1)

1.1.1 R is empty

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