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

Proof

1 Dependency Pair Transformation

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

1.1 Reduction Pair Processor with Usable Rules

Using the linear polynomial interpretation over the arctic semiring over the integers
[b#(x1)] = 8 · x1 + -∞
[b(x1)] = 8 · x1 + -∞
[a#(x1)] = 0 · x1 + -∞
[a(x1)] = 0 · x1 + -∞
[c(x1)] = 0 · x1 + -∞
together with the usable rules
a(x0) x0
a(a(b(x0))) c(b(a(a(x0))))
b(c(x0)) a(b(x0))
(w.r.t. the implicit argument filter of the reduction pair), the pairs
a#(a(b(x0))) b#(a(a(x0)))
b#(c(x0)) b#(x0)
b#(c(x0)) a#(b(x0))
remain.

1.1.1 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
[b#(x1)] =
1 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
1 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
[b(x1)] =
0 -∞ -∞
0 -∞ -∞
0 0 -∞
· x1 +
0 -∞ -∞
0 -∞ -∞
0 -∞ -∞
[a#(x1)] =
0 0 0
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
0 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
[a(x1)] =
0 -∞ -∞
0 0 0
0 0 1
· x1 +
0 -∞ -∞
0 -∞ -∞
1 -∞ -∞
[c(x1)] =
0 0 -∞
1 1 -∞
0 0 -∞
· x1 +
0 -∞ -∞
1 -∞ -∞
1 -∞ -∞
together with the usable rules
a(x0) x0
a(a(b(x0))) c(b(a(a(x0))))
b(c(x0)) a(b(x0))
(w.r.t. the implicit argument filter of the reduction pair), the pairs
a#(a(b(x0))) b#(a(a(x0)))
b#(c(x0)) b#(x0)
remain.

1.1.1.1 Dependency Graph Processor

The dependency pairs are split into 0 components.