Certification Problem

Input (TPDB TRS_Standard/Rubio_04/test829)

The rewrite relation of the following TRS is considered.

f(c(X,s(Y))) f(c(s(X),Y)) (1)
g(c(s(X),Y)) f(c(X,s(Y))) (2)

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)] = 2 · x1
[c(x1, x2)] = 1 · x1 + 2 · x2
[s(x1)] = 1 · x1
[g(x1)] = 2 + 2 · x1
all of the following rules can be deleted.
g(c(s(X),Y)) f(c(X,s(Y))) (2)

1.1 Rule Removal

Using the linear polynomial interpretation over the naturals
[f(x1)] = 2 · x1
[c(x1, x2)] = 1 · x1 + 2 · x2
[s(x1)] = 2 + 1 · x1
all of the following rules can be deleted.
f(c(X,s(Y))) f(c(s(X),Y)) (1)

1.1.1 R is empty

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