Certification Problem

Input (TPDB SRS_Standard/ICFP_2010/96403)

The rewrite relation of the following TRS is considered.

0(1(2(1(x1)))) → 3(1(1(x1))) (1)
0(2(4(5(0(x1))))) → 0(5(2(0(x1)))) (2)
0(4(3(5(5(x1))))) → 0(3(5(5(x1)))) (3)
1(1(4(4(3(x1))))) → 1(2(2(4(4(x1))))) (4)
5(1(5(5(5(4(x1)))))) → 5(2(4(1(1(4(x1)))))) (5)
0(1(3(3(4(3(3(x1))))))) → 0(3(2(0(3(x1))))) (6)
2(5(1(2(3(2(2(x1))))))) → 4(1(1(1(1(4(1(x1))))))) (7)
1(2(0(0(3(5(0(0(x1)))))))) → 5(1(0(4(0(5(3(2(x1)))))))) (8)
3(5(1(2(0(4(1(1(x1)))))))) → 3(5(4(0(3(4(1(x1))))))) (9)
2(0(2(4(0(0(3(1(2(x1))))))))) → 2(3(0(1(2(4(1(3(3(x1))))))))) (10)
3(0(0(4(0(1(1(0(5(3(x1)))))))))) → 0(1(0(0(4(3(2(4(3(x1))))))))) (11)
3(4(3(0(4(2(1(1(4(3(x1)))))))))) → 3(2(5(1(3(1(1(1(1(x1))))))))) (12)
4(0(2(0(3(4(3(0(3(0(4(x1))))))))))) → 4(4(5(2(0(3(2(4(1(5(4(x1))))))))))) (13)
4(1(0(2(5(4(5(2(4(4(5(x1))))))))))) → 2(0(2(0(1(2(5(1(4(5(x1)))))))))) (14)
3(1(4(0(3(1(0(3(0(2(4(4(x1)))))))))))) → 3(2(3(0(0(0(2(5(5(1(2(4(x1)))))))))))) (15)
0(3(1(1(2(2(3(5(1(5(5(4(0(x1))))))))))))) → 0(3(2(5(0(1(5(0(1(1(5(3(0(x1))))))))))))) (16)
1(3(3(5(2(5(2(4(5(3(0(2(4(x1))))))))))))) → 4(5(1(4(3(2(1(5(5(5(5(x1))))))))))) (17)
1(2(5(0(2(3(2(4(1(3(4(3(2(4(x1)))))))))))))) → 2(3(1(2(3(0(2(0(2(2(0(0(2(x1))))))))))))) (18)
5(4(3(5(0(3(0(3(1(0(1(1(1(2(x1)))))))))))))) → 5(2(3(1(4(1(5(5(1(4(2(0(x1)))))))))))) (19)
2(1(4(5(4(3(2(5(2(2(2(4(1(2(5(4(x1)))))))))))))))) → 2(3(0(0(1(1(2(4(1(4(5(5(0(3(x1)))))))))))))) (20)
1(5(2(3(5(2(3(0(5(5(0(1(0(3(1(5(0(x1))))))))))))))))) → 0(2(2(0(4(1(3(4(0(5(4(2(0(4(1(5(1(0(x1)))))))))))))))))) (21)
3(3(1(1(3(2(0(2(4(2(1(2(1(1(4(4(1(x1))))))))))))))))) → 1(2(2(2(3(3(0(2(4(5(3(4(0(4(1(4(1(x1))))))))))))))))) (22)
5(1(2(0(0(2(1(4(1(5(3(0(1(4(4(5(1(x1))))))))))))))))) → 5(5(2(5(4(5(4(2(5(2(5(1(0(2(3(1(x1)))))))))))))))) (23)
1(0(4(3(0(3(5(5(0(4(3(5(5(2(4(4(4(1(4(x1))))))))))))))))))) → 1(1(3(5(1(1(0(5(0(0(3(3(1(5(4(4(4(1(x1)))))))))))))))))) (24)
0(5(3(5(5(1(0(3(4(3(1(1(5(5(1(4(3(5(5(1(x1)))))))))))))))))))) → 0(0(5(1(2(1(1(4(4(4(2(3(1(5(5(5(1(4(2(x1))))))))))))))))))) (25)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by matchbox @ termCOMP 2023)

1 Closure Under Flat Contexts

Using the flat contexts

{5(☐), 4(☐), 3(☐), 2(☐), 1(☐), 0(☐)}

We obtain the transformed TRS

There are 150 ruless (increase limit for explicit display).

1.1 Semantic Labeling

The following interpretations form a model of the rules.

As carrier we take the set {0,...,5}. Symbols are labeled by the interpretation of their arguments using the interpretations (modulo 6):

[5(x1)] = 6x1 + 0
[4(x1)] = 6x1 + 1
[3(x1)] = 6x1 + 2
[2(x1)] = 6x1 + 3
[1(x1)] = 6x1 + 4
[0(x1)] = 6x1 + 5

We obtain the labeled TRS

There are 900 ruless (increase limit for explicit display).

1.1.1 Rule Removal

Using the matrix interpretations of dimension 1 with strict dimension 1 over the rationals with delta = 1
[50(x1)] = x1 +
80/11
[51(x1)] = x1 +
940/11
[52(x1)] = x1 +
6331/11
[53(x1)] = x1 +
6439/11
[54(x1)] = x1 +
6439/11
[55(x1)] = x1 +
6298/11
[40(x1)] = x1 +
4498/11
[41(x1)] = x1 +
6439/11
[42(x1)] = x1 +
6450/11
[43(x1)] = x1 +
1410/11
[44(x1)] = x1 +
0
[45(x1)] = x1 +
3995/11
[30(x1)] = x1 +
6560/11
[31(x1)] = x1 +
6450/11
[32(x1)] = x1 +
6472/11
[33(x1)] = x1 +
1421/11
[34(x1)] = x1 +
6439/11
[35(x1)] = x1 +
4028/11
[20(x1)] = x1 +
6439/11
[21(x1)] = x1 +
47
[22(x1)] = x1 +
3
[23(x1)] = x1 +
0
[24(x1)] = x1 +
6560/11
[25(x1)] = x1 +
0
[10(x1)] = x1 +
3
[11(x1)] = x1 +
1
[12(x1)] = x1 +
6439/11
[13(x1)] = x1 +
6439/11
[14(x1)] = x1 +
48
[15(x1)] = x1 +
50
[00(x1)] = x1 +
3
[01(x1)] = x1 +
4451/11
[02(x1)] = x1 +
6439/11
[03(x1)] = x1 +
11
[04(x1)] = x1 +
0
[05(x1)] = x1 +
6439/11
all of the following rules can be deleted.

There are 900 ruless (increase limit for explicit display).

1.1.1.1 R is empty

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