YES Termination Proof

Termination Proof

by ttt2 (version ttt2 1.15)

Input

The rewrite relation of the following TRS is considered.

a(x0) x0
a(b(x0)) c(b(x0))
b(x0) a(a(c(x0)))
c(c(x0)) b(x0)

Proof

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
a#(b(x0)) c#(b(x0))
b#(x0) c#(x0)
b#(x0) a#(c(x0))
b#(x0) a#(a(c(x0)))
c#(c(x0)) b#(x0)

1.1 Reduction Pair Processor with Usable Rules

Using the linear polynomial interpretation over (3 x 3)-matrices with strict dimension 1 over the arctic semiring over the integers
[c#(x1)] =
1 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
0 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
[b(x1)] =
0 0 0
1 1 1
1 1 1
· x1 +
0 -∞ -∞
1 -∞ -∞
1 -∞ -∞
[a#(x1)] =
0 0 -∞
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
0 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
[b#(x1)] =
1 1 1
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
1 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
[a(x1)] =
0 0 -∞
-∞ 0 -∞
0 1 0
· x1 +
0 -∞ -∞
0 -∞ -∞
0 -∞ -∞
[c(x1)] =
0 0 0
0 0 0
1 1 1
· x1 +
0 -∞ -∞
0 -∞ -∞
1 -∞ -∞
together with the usable rules
a(x0) x0
a(b(x0)) c(b(x0))
b(x0) a(a(c(x0)))
c(c(x0)) b(x0)
(w.r.t. the implicit argument filter of the reduction pair), the pairs
a#(b(x0)) c#(b(x0))
b#(x0) c#(x0)
c#(c(x0)) b#(x0)
remain.

1.1.1 Dependency Graph Processor

The dependency pairs are split into 0 components.