YES Termination Proof

Termination Proof

by ttt2 (version ttt2 1.15)

Input

The rewrite relation of the following TRS is considered.

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

Proof

1 Rule Removal

Using the linear polynomial interpretation over the arctic semiring over the integers
[a(x1)] = 1 · x1 + -∞
[b(x1)] = 3 · x1 + -∞
the rules
a(a(a(b(b(x0))))) b(b(b(x0)))
b(a(a(a(b(x0))))) a(a(a(b(a(a(a(x0)))))))
remain.

1.1 Dependency Pair Transformation

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

1.1.1 Reduction Pair Processor with Usable Rules

Using the linear polynomial interpretation over the arctic semiring over the integers
[a(x1)] = 1 · x1 + -∞
[b#(x1)] = 4 · x1 + -∞
[b(x1)] = 3 · x1 + -∞
[a#(x1)] = 2 · x1 + -∞
together with the usable rules
a(a(a(b(b(x0))))) b(b(b(x0)))
b(a(a(a(b(x0))))) a(a(a(b(a(a(a(x0)))))))
(w.r.t. the implicit argument filter of the reduction pair), the pairs
a#(a(a(b(b(x0))))) b#(b(b(x0)))
b#(a(a(a(b(x0))))) a#(a(a(b(a(a(a(x0)))))))
remain.

1.1.1.1 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
[a(x1)] =
0 0 0
-∞ 0 0
-∞ 0 0
· x1 +
0 -∞ -∞
0 -∞ -∞
0 -∞ -∞
[b#(x1)] =
0 -∞ 1
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
0 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
[b(x1)] =
0 0 1
0 0 0
-∞ -∞ 0
· x1 +
1 -∞ -∞
0 -∞ -∞
0 -∞ -∞
[a#(x1)] =
-∞ 0 0
-∞ -∞ -∞
-∞ -∞ -∞
· x1 +
0 -∞ -∞
-∞ -∞ -∞
-∞ -∞ -∞
together with the usable rules
a(a(a(b(b(x0))))) b(b(b(x0)))
b(a(a(a(b(x0))))) a(a(a(b(a(a(a(x0)))))))
(w.r.t. the implicit argument filter of the reduction pair), the pair
a#(a(a(b(b(x0))))) b#(b(b(x0)))
remains.

1.1.1.1.1 Dependency Graph Processor

The dependency pairs are split into 0 components.