Certification Problem

Input (TPDB SRS_Standard/Trafo_06/hom02)

The rewrite relation of the following TRS is considered.

a(x1) b(b(x1)) (1)
a(b(b(x1))) b(b(c(c(c(a(x1)))))) (2)
b(b(x1)) c(c(c(x1))) (3)
c(c(c(b(b(x1))))) a(x1) (4)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by NaTT @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
a#(b(b(x1))) b#(c(c(c(a(x1))))) (5)
a#(b(b(x1))) a#(x1) (6)
b#(b(x1)) c#(x1) (7)
a#(x1) b#(x1) (8)
c#(c(c(b(b(x1))))) a#(x1) (9)
b#(b(x1)) c#(c(c(x1))) (10)
a#(x1) b#(b(x1)) (11)
a#(b(b(x1))) c#(a(x1)) (12)
a#(b(b(x1))) c#(c(c(a(x1)))) (13)
a#(b(b(x1))) b#(b(c(c(c(a(x1)))))) (14)
b#(b(x1)) c#(c(x1)) (15)
a#(b(b(x1))) c#(c(a(x1))) (16)

1.1 Dependency Graph Processor

The dependency pairs are split into 1 component.