Certification Problem

Input (TPDB TRS_Standard/SK90/2.60)

The rewrite relation of the following TRS is considered.

f(g(f(a),h(a,f(a)))) f(h(g(f(a),a),g(f(a),f(a)))) (1)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Rule Removal

Using the linear polynomial interpretation over the naturals
[f(x1)] = 1 · x1
[g(x1, x2)] = 2 · x1 + 2 · x2
[a] = 0
[h(x1, x2)] = 1 + 2 · x1 + 1 · x2
all of the following rules can be deleted.
f(g(f(a),h(a,f(a)))) f(h(g(f(a),a),g(f(a),f(a)))) (1)

1.1 R is empty

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