Certification Problem

Input (TPDB SRS_Standard/ICFP_2010/39849)

The rewrite relation of the following TRS is considered.

0(1(2(x1))) → 0(2(1(1(x1)))) (1)
0(3(2(x1))) → 0(2(1(3(x1)))) (2)
2(4(1(x1))) → 4(2(1(1(x1)))) (3)
0(0(3(2(x1)))) → 0(0(2(1(3(x1))))) (4)
0(1(0(3(x1)))) → 0(1(1(3(0(x1))))) (5)
0(1(0(5(x1)))) → 0(0(1(1(5(x1))))) (6)
0(1(2(2(x1)))) → 0(2(1(1(2(x1))))) (7)
0(1(2(3(x1)))) → 0(2(1(3(1(x1))))) (8)
0(1(2(5(x1)))) → 2(1(1(0(5(x1))))) (9)
0(1(4(1(x1)))) → 0(4(1(1(1(x1))))) (10)
0(1(4(2(x1)))) → 0(0(2(1(4(x1))))) (11)
0(1(4(2(x1)))) → 0(4(0(2(1(x1))))) (12)
0(1(4(3(x1)))) → 4(0(1(1(3(x1))))) (13)
0(1(4(5(x1)))) → 0(1(1(5(4(x1))))) (14)
0(1(5(2(x1)))) → 0(2(5(1(1(x1))))) (15)
0(2(0(3(x1)))) → 0(0(2(3(1(x1))))) (16)
0(3(0(1(x1)))) → 0(0(1(3(1(x1))))) (17)
0(3(0(2(x1)))) → 0(0(2(3(1(x1))))) (18)
0(3(0(3(x1)))) → 0(0(3(1(3(x1))))) (19)
0(3(2(0(x1)))) → 0(2(1(3(0(x1))))) (20)
0(3(5(1(x1)))) → 0(5(3(1(1(x1))))) (21)
0(4(0(1(x1)))) → 0(0(4(1(1(x1))))) (22)
0(5(2(0(x1)))) → 2(1(5(0(0(x1))))) (23)
2(1(2(3(x1)))) → 2(1(1(3(2(x1))))) (24)
2(1(4(1(x1)))) → 4(2(1(1(1(x1))))) (25)
2(2(0(3(x1)))) → 2(0(2(1(3(x1))))) (26)
2(2(4(1(x1)))) → 2(4(2(1(1(x1))))) (27)
2(3(1(4(x1)))) → 2(1(1(3(4(x1))))) (28)
2(4(1(4(x1)))) → 4(4(2(1(1(x1))))) (29)
2(4(3(1(x1)))) → 4(2(3(1(1(x1))))) (30)
2(5(0(1(x1)))) → 0(2(5(1(1(x1))))) (31)
2(5(0(3(x1)))) → 5(0(2(1(3(x1))))) (32)
3(0(1(0(x1)))) → 3(1(0(0(0(x1))))) (33)
3(0(1(4(x1)))) → 3(1(1(0(4(x1))))) (34)
3(0(3(0(x1)))) → 3(1(3(0(0(x1))))) (35)
3(1(0(3(x1)))) → 3(1(1(3(0(x1))))) (36)
3(1(2(1(x1)))) → 1(3(2(1(1(x1))))) (37)
3(1(2(1(x1)))) → 3(2(1(1(1(x1))))) (38)
3(2(0(1(x1)))) → 1(3(0(2(1(x1))))) (39)
3(2(0(1(x1)))) → 3(1(0(2(1(x1))))) (40)
3(4(1(2(x1)))) → 3(2(1(1(4(x1))))) (41)
3(5(1(4(x1)))) → 3(1(1(5(4(x1))))) (42)
4(1(0(1(x1)))) → 4(0(1(1(1(x1))))) (43)
4(1(2(1(x1)))) → 2(4(1(1(1(x1))))) (44)
4(1(4(3(x1)))) → 4(1(1(3(4(x1))))) (45)
4(2(4(1(x1)))) → 4(4(2(1(1(x1))))) (46)
4(4(1(2(x1)))) → 4(2(1(1(4(x1))))) (47)
4(5(0(1(x1)))) → 5(0(4(1(1(x1))))) (48)
5(1(0(3(x1)))) → 5(0(1(1(3(x1))))) (49)
5(1(0(3(x1)))) → 5(1(1(3(0(x1))))) (50)
5(1(3(1(x1)))) → 5(3(1(1(1(x1))))) (51)
5(1(4(3(x1)))) → 4(1(1(3(5(x1))))) (52)
5(1(4(4(x1)))) → 4(1(1(5(4(x1))))) (53)
5(1(5(3(x1)))) → 5(5(1(1(3(x1))))) (54)
5(2(0(1(x1)))) → 2(0(5(1(1(x1))))) (55)
5(2(0(5(x1)))) → 5(0(2(1(5(x1))))) (56)
5(3(4(1(x1)))) → 5(4(3(1(1(x1))))) (57)
5(4(0(1(x1)))) → 5(0(4(1(1(x1))))) (58)
5(4(1(0(x1)))) → 4(1(1(5(0(x1))))) (59)
5(4(1(0(x1)))) → 5(1(1(4(0(x1))))) (60)

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 360 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 2160 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 +
9
[51(x1)] = x1 +
0
[52(x1)] = x1 +
9
[53(x1)] = x1 +
0
[54(x1)] = x1 +
10
[55(x1)] = x1 +
0
[40(x1)] = x1 +
9
[41(x1)] = x1 +
2
[42(x1)] = x1 +
9
[43(x1)] = x1 +
0
[44(x1)] = x1 +
9
[45(x1)] = x1 +
0
[30(x1)] = x1 +
0
[31(x1)] = x1 +
2
[32(x1)] = x1 +
33
[33(x1)] = x1 +
0
[34(x1)] = x1 +
9
[35(x1)] = x1 +
13
[20(x1)] = x1 +
9
[21(x1)] = x1 +
9
[22(x1)] = x1 +
9
[23(x1)] = x1 +
9
[24(x1)] = x1 +
2
[25(x1)] = x1 +
1
[10(x1)] = x1 +
2
[11(x1)] = x1 +
9
[12(x1)] = x1 +
1
[13(x1)] = x1 +
11
[14(x1)] = x1 +
0
[15(x1)] = x1 +
11
[00(x1)] = x1 +
13
[01(x1)] = x1 +
2
[02(x1)] = x1 +
30
[03(x1)] = x1 +
0
[04(x1)] = x1 +
33
[05(x1)] = x1 +
1
all of the following rules can be deleted.

There are 2160 ruless (increase limit for explicit display).

1.1.1.1 R is empty

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