Certification Problem

Input (TPDB SRS_Standard/Waldmann_07_size12/size-12-alpha-3-num-495)

The rewrite relation of the following TRS is considered.

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

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by matchbox @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
c#(b(x1)) c#(c(a(x1))) (4)
c#(b(x1)) c#(a(x1)) (5)
c#(b(x1)) b#(c(c(a(x1)))) (6)
c#(b(x1)) a#(x1) (7)
b#(c(x1)) a#(x1) (8)
a#(a(x1)) b#(x1) (9)

1.1 Monotonic Reduction Pair Processor with Usable Rules

Using the matrix interpretations of dimension 1 with strict dimension 1 over the rationals with delta = 1
[c(x1)] = x1 +
0
[b(x1)] = x1 +
0
[a(x1)] = x1 +
0
[c#(x1)] = x1 +
1
[b#(x1)] = x1 +
0
[a#(x1)] = x1 +
0
together with the usable rules
a(a(x1)) b(x1) (1)
b(c(x1)) a(x1) (2)
c(b(x1)) b(c(c(a(x1)))) (3)
(w.r.t. the implicit argument filter of the reduction pair), the pairs
c#(b(x1)) b#(c(c(a(x1)))) (6)
c#(b(x1)) a#(x1) (7)
and no rules could be deleted.

1.1.1 Dependency Graph Processor

The dependency pairs are split into 2 components.