Certification Problem

Input (TPDB SRS_Standard/Waldmann_07_size12/size-12-alpha-3-num-378)

The rewrite relation of the following TRS is considered.

a(x1) b(x1) (1)
a(c(b(x1))) c(a(b(a(c(x1))))) (2)
b(c(x1)) x1 (3)

Property / Task

Prove or disprove termination.

Answer / Result

No.

Proof (by AProVE @ termCOMP 2023)

1 Looping derivation

There is a looping derivation.

a c b b b c c b b+ c c a b a c b b b c c b b ε

The derivation can be derived as follows.