YES Termination Proof

Termination Proof

by ttt2 (version ttt2 1.15)

Input

The rewrite relation of the following TRS is considered.

c(c(x0)) a(a(a(b(b(b(x0))))))
b(b(b(a(x0)))) b(b(b(b(b(b(b(b(x0))))))))
b(b(c(c(x0)))) c(c(c(a(a(a(a(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)] =
0 0
0 0
· x1 +
-∞ -∞
-∞ -∞
[c(x1)] =
0 1
0 0
· x1 +
-∞ -∞
-∞ -∞
[a(x1)] =
0 0
-∞ -∞
· x1 +
-∞ -∞
-∞ -∞
the rules
b(b(b(a(x0)))) b(b(b(b(b(b(b(b(x0))))))))
b(b(c(c(x0)))) c(c(c(a(a(a(a(x0)))))))
remain.

1.1 String Reversal

Since only unary symbols occur, one can reverse all terms and obtains the TRS
a(b(b(b(x0)))) b(b(b(b(b(b(b(b(x0))))))))
c(c(b(b(x0)))) a(a(a(a(c(c(c(x0)))))))

1.1.1 Bounds

The given TRS is match-bounded by 0. This is shown by the following automaton.