Certification Problem

Input (TPDB SRS_Standard/Zantema_04/z059)

The rewrite relation of the following TRS is considered.

b(a(b(b(b(b(x1)))))) a(b(b(b(b(b(a(x1))))))) (1)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
b#(a(b(b(b(b(x1)))))) b#(b(b(b(b(a(x1)))))) (2)
b#(a(b(b(b(b(x1)))))) b#(b(b(b(a(x1))))) (3)
b#(a(b(b(b(b(x1)))))) b#(b(b(a(x1)))) (4)
b#(a(b(b(b(b(x1)))))) b#(b(a(x1))) (5)
b#(a(b(b(b(b(x1)))))) b#(a(x1)) (6)

1.1 Reduction Pair Processor

Using the linear polynomial interpretation over the naturals
[b#(x1)] = 1 · x1
[a(x1)] = 1 · x1
[b(x1)] = 1 + 1 · x1
the pairs
b#(a(b(b(b(b(x1)))))) b#(b(b(b(a(x1))))) (3)
b#(a(b(b(b(b(x1)))))) b#(b(b(a(x1)))) (4)
b#(a(b(b(b(b(x1)))))) b#(b(a(x1))) (5)
b#(a(b(b(b(b(x1)))))) b#(a(x1)) (6)
could be deleted.

1.1.1 Reduction Pair Processor

Using the matrix interpretations of dimension 3 with strict dimension 1 over the arctic semiring over the naturals
[b#(x1)] =
-∞
-∞
-∞
+
0 0 0
-∞ -∞ -∞
-∞ -∞ -∞
· x1
[a(x1)] =
0
0
-∞
+
-∞ -∞ 0
0 -∞ 1
-∞ -∞ -∞
· x1
[b(x1)] =
1
0
0
+
0 0 1
-∞ 0 0
0 -∞ 0
· x1
the pair
b#(a(b(b(b(b(x1)))))) b#(b(b(b(b(a(x1)))))) (2)
could be deleted.

1.1.1.1 P is empty

There are no pairs anymore.