Certification Problem

Input (TPDB SRS_Standard/Waldmann_06_SRS/uni-2)

The rewrite relation of the following TRS is considered.

a(a(a(a(x1)))) a(c(a(c(c(x1))))) (1)
c(c(c(x1))) a(a(a(x1))) (2)

Property / Task

Prove or disprove termination.

Answer / Result

No.

Proof (by AProVE @ termCOMP 2023)

1 Looping derivation

There is a looping derivation.

a a a a c a a a c a a c a+ a c a a a a c a a a c a a c a c c

The derivation can be derived as follows.