Certification Problem

Input (TPDB SRS_Relative/Mixed_relative_SRS/zr01)

The relative rewrite relation R/S is considered where R is the following TRS

n(s(x1)) s(x1) (1)
o(s(x1)) s(x1) (2)

and S is the following TRS.

t(x1) t(c(n(x1))) (3)
c(n(x1)) n(c(x1)) (4)
c(o(x1)) o(c(x1)) (5)
c(o(x1)) o(x1) (6)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Rule Removal

Using the linear polynomial interpretation over the naturals
[n(x1)] = 1 · x1
[s(x1)] = 1 · x1
[o(x1)] = 1 + 1 · x1
[t(x1)] = 1 · x1
[c(x1)] = 1 · x1
all of the following rules can be deleted.
o(s(x1)) s(x1) (2)

1.1 Rule Removal

Using the matrix interpretations of dimension 2 with strict dimension 1 over the integers
[n(x1)] =
0
0
+
1 2
0 2
· x1
[s(x1)] =
0
2
+
1 0
0 0
· x1
[t(x1)] =
2
2
+
1 2
0 0
· x1
[c(x1)] =
0
0
+
1 0
0 0
· x1
[o(x1)] =
0
0
+
1 0
0 0
· x1
all of the following rules can be deleted.
n(s(x1)) s(x1) (1)

1.1.1 R is empty

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