YES Termination Proof

Termination Proof

by ttt2 (version ttt2 1.15)

Input

The rewrite relation of the following TRS is considered.

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

Proof

1 Rule Removal

Using the linear polynomial interpretation over (2 x 2)-matrices with strict dimension 1 over the arctic semiring over the integers
[b(x1)] =
3 3
1 3
· x1 +
-∞ -∞
-∞ -∞
[c(x1)] =
3 0
2 3
· x1 +
-∞ -∞
-∞ -∞
[a(x1)] =
0 2
1 1
· x1 +
-∞ -∞
-∞ -∞
the rules
b(c(x0)) c(b(x0))
a(a(a(a(x0)))) b(c(x0))
remain.

1.1 Rule Removal

Using the linear polynomial interpretation over the arctic semiring over the integers
[b(x1)] = 4 · x1 + -∞
[c(x1)] = 2 · x1 + -∞
[a(x1)] = 2 · x1 + -∞
the rule
b(c(x0)) c(b(x0))
remains.

1.1.1 Rule Removal

Using the Knuth Bendix order with w0 = 1 and the following precedence and weight function
prec(b) = 1 weight(b) = 1
prec(c) = 0 weight(c) = 1
all rules could be removed.

1.1.1.1 R is empty

There are no rules in the TRS. Hence, it is terminating.