Certification Problem

Input (TPDB SRS_Standard/ICFP_2010/160263)

The rewrite relation of the following TRS is considered.

0(1(2(2(x1)))) → 0(1(0(2(2(x1))))) (1)
0(1(2(2(x1)))) → 0(1(2(3(2(x1))))) (2)
0(1(2(2(x1)))) → 0(2(2(1(3(x1))))) (3)
0(1(2(2(x1)))) → 1(0(3(2(2(x1))))) (4)
0(1(2(2(x1)))) → 1(2(0(3(2(x1))))) (5)
0(1(2(2(x1)))) → 1(3(0(2(2(x1))))) (6)
0(1(2(2(x1)))) → 1(3(2(0(2(x1))))) (7)
0(1(2(2(x1)))) → 0(1(0(4(2(2(x1)))))) (8)
0(1(2(2(x1)))) → 0(2(1(3(2(3(x1)))))) (9)
0(1(2(2(x1)))) → 1(2(1(0(4(2(x1)))))) (10)
0(1(2(2(x1)))) → 1(5(0(4(2(2(x1)))))) (11)
0(1(2(2(x1)))) → 2(0(3(1(3(2(x1)))))) (12)
0(1(2(2(x1)))) → 2(1(1(0(4(2(x1)))))) (13)
0(1(2(2(x1)))) → 2(1(3(0(2(0(x1)))))) (14)
0(1(2(2(x1)))) → 2(1(3(3(2(0(x1)))))) (15)
0(1(2(2(x1)))) → 2(1(5(3(0(2(x1)))))) (16)
0(1(2(2(x1)))) → 2(2(1(3(0(5(x1)))))) (17)
0(1(2(2(x1)))) → 2(4(1(3(2(0(x1)))))) (18)
0(1(4(5(x1)))) → 1(5(0(4(1(x1))))) (19)
0(1(4(5(x1)))) → 5(0(4(1(5(x1))))) (20)
0(1(4(5(x1)))) → 5(4(1(5(0(x1))))) (21)
0(1(4(5(x1)))) → 1(1(5(0(4(1(x1)))))) (22)
0(1(4(5(x1)))) → 5(4(1(5(5(0(x1)))))) (23)
5(1(2(2(x1)))) → 1(0(2(2(5(x1))))) (24)
5(1(2(2(x1)))) → 1(3(5(2(2(x1))))) (25)
5(1(2(2(x1)))) → 1(5(2(3(2(x1))))) (26)
5(1(2(2(x1)))) → 1(5(0(2(2(3(x1)))))) (27)
5(1(2(2(x1)))) → 2(1(0(3(2(5(x1)))))) (28)
5(1(2(2(x1)))) → 3(1(3(5(2(2(x1)))))) (29)
5(1(2(2(x1)))) → 4(1(3(2(2(5(x1)))))) (30)
5(1(2(2(x1)))) → 5(1(0(4(2(2(x1)))))) (31)
5(1(2(2(x1)))) → 5(1(2(0(4(2(x1)))))) (32)
0(1(1(4(5(x1))))) → 3(1(0(4(1(5(x1)))))) (33)
0(1(2(2(2(x1))))) → 1(0(2(2(5(2(x1)))))) (34)
0(1(2(2(5(x1))))) → 1(5(0(4(2(2(x1)))))) (35)
0(1(2(4(5(x1))))) → 2(5(1(0(4(5(x1)))))) (36)
0(1(4(5(2(x1))))) → 1(0(4(2(0(5(x1)))))) (37)
0(1(4(5(5(x1))))) → 5(0(4(0(1(5(x1)))))) (38)
0(1(5(4(5(x1))))) → 1(5(0(4(1(5(x1)))))) (39)
0(5(1(2(2(x1))))) → 0(1(3(2(5(2(x1)))))) (40)
3(3(1(2(2(x1))))) → 1(3(2(0(3(2(x1)))))) (41)
3(4(4(0(5(x1))))) → 3(5(4(5(0(4(x1)))))) (42)
5(0(1(2(2(x1))))) → 1(3(2(0(5(2(x1)))))) (43)
5(1(2(2(5(x1))))) → 1(5(2(3(2(5(x1)))))) (44)
5(2(1(2(2(x1))))) → 2(1(3(5(2(2(x1)))))) (45)
5(2(4(0(5(x1))))) → 0(4(2(5(5(5(x1)))))) (46)
5(2(4(0(5(x1))))) → 0(4(5(4(2(5(x1)))))) (47)

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 282 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 1692 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 +
3
[51(x1)] = x1 +
0
[52(x1)] = x1 +
3
[53(x1)] = x1 +
3
[54(x1)] = x1 +
8
[55(x1)] = x1 +
0
[40(x1)] = x1 +
8
[41(x1)] = x1 +
11
[42(x1)] = x1 +
0
[43(x1)] = x1 +
0
[44(x1)] = x1 +
0
[45(x1)] = x1 +
11
[30(x1)] = x1 +
0
[31(x1)] = x1 +
3
[32(x1)] = x1 +
0
[33(x1)] = x1 +
0
[34(x1)] = x1 +
0
[35(x1)] = x1 +
0
[20(x1)] = x1 +
0
[21(x1)] = x1 +
8
[22(x1)] = x1 +
8
[23(x1)] = x1 +
9
[24(x1)] = x1 +
3
[25(x1)] = x1 +
0
[10(x1)] = x1 +
1
[11(x1)] = x1 +
8
[12(x1)] = x1 +
0
[13(x1)] = x1 +
11
[14(x1)] = x1 +
0
[15(x1)] = x1 +
1
[00(x1)] = x1 +
0
[01(x1)] = x1 +
0
[02(x1)] = x1 +
0
[03(x1)] = x1 +
0
[04(x1)] = x1 +
9
[05(x1)] = x1 +
8
all of the following rules can be deleted.

There are 1692 ruless (increase limit for explicit display).

1.1.1.1 R is empty

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