Certification Problem

Input (TPDB SRS_Standard/ICFP_2010/213560)

The rewrite relation of the following TRS is considered.

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

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 288 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 1728 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 +
1
[52(x1)] = x1 +
0
[53(x1)] = x1 +
0
[54(x1)] = x1 +
0
[55(x1)] = x1 +
3
[40(x1)] = x1 +
108
[41(x1)] = x1 +
107
[42(x1)] = x1 +
0
[43(x1)] = x1 +
50
[44(x1)] = x1 +
0
[45(x1)] = x1 +
50
[30(x1)] = x1 +
0
[31(x1)] = x1 +
107
[32(x1)] = x1 +
6
[33(x1)] = x1 +
3
[34(x1)] = x1 +
126
[35(x1)] = x1 +
0
[20(x1)] = x1 +
6
[21(x1)] = x1 +
107
[22(x1)] = x1 +
0
[23(x1)] = x1 +
6
[24(x1)] = x1 +
0
[25(x1)] = x1 +
113
[10(x1)] = x1 +
1
[11(x1)] = x1 +
50
[12(x1)] = x1 +
0
[13(x1)] = x1 +
107
[14(x1)] = x1 +
0
[15(x1)] = x1 +
157
[00(x1)] = x1 +
1
[01(x1)] = x1 +
0
[02(x1)] = x1 +
3
[03(x1)] = x1 +
19
[04(x1)] = x1 +
6
[05(x1)] = x1 +
0
all of the following rules can be deleted.

There are 1728 ruless (increase limit for explicit display).

1.1.1.1 R is empty

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