Certification Problem

Input (TPDB SRS_Relative/Waldmann_19/random-78)

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

a(c(b(x1))) → b(a(b(x1))) (1)
a(b(c(x1))) → b(b(c(x1))) (2)

and S is the following TRS.

a(b(c(x1))) → c(c(b(x1))) (3)
b(a(c(x1))) → c(a(c(x1))) (4)
b(c(a(x1))) → a(c(b(x1))) (5)
a(a(a(x1))) → c(a(b(x1))) (6)
a(a(c(x1))) → a(a(b(x1))) (7)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Closure Under Flat Contexts

Using the flat contexts

{a(☐), c(☐), b(☐)}

We obtain the transformed TRS
a(a(c(b(x1)))) → a(b(a(b(x1)))) (8)
c(a(c(b(x1)))) → c(b(a(b(x1)))) (9)
b(a(c(b(x1)))) → b(b(a(b(x1)))) (10)
a(a(b(c(x1)))) → a(b(b(c(x1)))) (11)
c(a(b(c(x1)))) → c(b(b(c(x1)))) (12)
b(a(b(c(x1)))) → b(b(b(c(x1)))) (13)
a(a(c(x1))) → a(a(b(x1))) (7)
a(a(b(c(x1)))) → a(c(c(b(x1)))) (14)
c(a(b(c(x1)))) → c(c(c(b(x1)))) (15)
b(a(b(c(x1)))) → b(c(c(b(x1)))) (16)
a(b(a(c(x1)))) → a(c(a(c(x1)))) (17)
c(b(a(c(x1)))) → c(c(a(c(x1)))) (18)
b(b(a(c(x1)))) → b(c(a(c(x1)))) (19)
a(b(c(a(x1)))) → a(a(c(b(x1)))) (20)
c(b(c(a(x1)))) → c(a(c(b(x1)))) (21)
b(b(c(a(x1)))) → b(a(c(b(x1)))) (22)
a(a(a(a(x1)))) → a(c(a(b(x1)))) (23)
c(a(a(a(x1)))) → c(c(a(b(x1)))) (24)
b(a(a(a(x1)))) → b(c(a(b(x1)))) (25)

1.1 Semantic Labeling

Root-labeling is applied.

We obtain the labeled TRS
aa(ac(cb(ba(x1)))) → ab(ba(ab(ba(x1)))) (26)
aa(ac(cb(bc(x1)))) → ab(ba(ab(bc(x1)))) (27)
aa(ac(cb(bb(x1)))) → ab(ba(ab(bb(x1)))) (28)
ca(ac(cb(ba(x1)))) → cb(ba(ab(ba(x1)))) (29)
ca(ac(cb(bc(x1)))) → cb(ba(ab(bc(x1)))) (30)
ca(ac(cb(bb(x1)))) → cb(ba(ab(bb(x1)))) (31)
ba(ac(cb(ba(x1)))) → bb(ba(ab(ba(x1)))) (32)
ba(ac(cb(bc(x1)))) → bb(ba(ab(bc(x1)))) (33)
ba(ac(cb(bb(x1)))) → bb(ba(ab(bb(x1)))) (34)
aa(ab(bc(ca(x1)))) → ab(bb(bc(ca(x1)))) (35)
aa(ab(bc(cc(x1)))) → ab(bb(bc(cc(x1)))) (36)
aa(ab(bc(cb(x1)))) → ab(bb(bc(cb(x1)))) (37)
ca(ab(bc(ca(x1)))) → cb(bb(bc(ca(x1)))) (38)
ca(ab(bc(cc(x1)))) → cb(bb(bc(cc(x1)))) (39)
ca(ab(bc(cb(x1)))) → cb(bb(bc(cb(x1)))) (40)
ba(ab(bc(ca(x1)))) → bb(bb(bc(ca(x1)))) (41)
ba(ab(bc(cc(x1)))) → bb(bb(bc(cc(x1)))) (42)
ba(ab(bc(cb(x1)))) → bb(bb(bc(cb(x1)))) (43)
aa(ac(ca(x1))) → aa(ab(ba(x1))) (44)
aa(ac(cc(x1))) → aa(ab(bc(x1))) (45)
aa(ac(cb(x1))) → aa(ab(bb(x1))) (46)
aa(ab(bc(ca(x1)))) → ac(cc(cb(ba(x1)))) (47)
aa(ab(bc(cc(x1)))) → ac(cc(cb(bc(x1)))) (48)
aa(ab(bc(cb(x1)))) → ac(cc(cb(bb(x1)))) (49)
ca(ab(bc(ca(x1)))) → cc(cc(cb(ba(x1)))) (50)
ca(ab(bc(cc(x1)))) → cc(cc(cb(bc(x1)))) (51)
ca(ab(bc(cb(x1)))) → cc(cc(cb(bb(x1)))) (52)
ba(ab(bc(ca(x1)))) → bc(cc(cb(ba(x1)))) (53)
ba(ab(bc(cc(x1)))) → bc(cc(cb(bc(x1)))) (54)
ba(ab(bc(cb(x1)))) → bc(cc(cb(bb(x1)))) (55)
ab(ba(ac(ca(x1)))) → ac(ca(ac(ca(x1)))) (56)
ab(ba(ac(cc(x1)))) → ac(ca(ac(cc(x1)))) (57)
ab(ba(ac(cb(x1)))) → ac(ca(ac(cb(x1)))) (58)
cb(ba(ac(ca(x1)))) → cc(ca(ac(ca(x1)))) (59)
cb(ba(ac(cc(x1)))) → cc(ca(ac(cc(x1)))) (60)
cb(ba(ac(cb(x1)))) → cc(ca(ac(cb(x1)))) (61)
bb(ba(ac(ca(x1)))) → bc(ca(ac(ca(x1)))) (62)
bb(ba(ac(cc(x1)))) → bc(ca(ac(cc(x1)))) (63)
bb(ba(ac(cb(x1)))) → bc(ca(ac(cb(x1)))) (64)
ab(bc(ca(aa(x1)))) → aa(ac(cb(ba(x1)))) (65)
ab(bc(ca(ac(x1)))) → aa(ac(cb(bc(x1)))) (66)
ab(bc(ca(ab(x1)))) → aa(ac(cb(bb(x1)))) (67)
cb(bc(ca(aa(x1)))) → ca(ac(cb(ba(x1)))) (68)
cb(bc(ca(ac(x1)))) → ca(ac(cb(bc(x1)))) (69)
cb(bc(ca(ab(x1)))) → ca(ac(cb(bb(x1)))) (70)
bb(bc(ca(aa(x1)))) → ba(ac(cb(ba(x1)))) (71)
bb(bc(ca(ac(x1)))) → ba(ac(cb(bc(x1)))) (72)
bb(bc(ca(ab(x1)))) → ba(ac(cb(bb(x1)))) (73)
aa(aa(aa(aa(x1)))) → ac(ca(ab(ba(x1)))) (74)
aa(aa(aa(ac(x1)))) → ac(ca(ab(bc(x1)))) (75)
aa(aa(aa(ab(x1)))) → ac(ca(ab(bb(x1)))) (76)
ca(aa(aa(aa(x1)))) → cc(ca(ab(ba(x1)))) (77)
ca(aa(aa(ac(x1)))) → cc(ca(ab(bc(x1)))) (78)
ca(aa(aa(ab(x1)))) → cc(ca(ab(bb(x1)))) (79)
ba(aa(aa(aa(x1)))) → bc(ca(ab(ba(x1)))) (80)
ba(aa(aa(ac(x1)))) → bc(ca(ab(bc(x1)))) (81)
ba(aa(aa(ab(x1)))) → bc(ca(ab(bb(x1)))) (82)

1.1.1 Rule Removal

Using the linear polynomial interpretation over the naturals
[aa(x1)] = 1 + 1 · x1
[ac(x1)] = 1 · x1
[cb(x1)] = 1 · x1
[ba(x1)] = 1 + 1 · x1
[ab(x1)] = 1 · x1
[bc(x1)] = 1 · x1
[bb(x1)] = 1 · x1
[ca(x1)] = 1 + 1 · x1
[cc(x1)] = 1 · x1
all of the following rules can be deleted.
aa(ab(bc(ca(x1)))) → ab(bb(bc(ca(x1)))) (35)
aa(ab(bc(cc(x1)))) → ab(bb(bc(cc(x1)))) (36)
aa(ab(bc(cb(x1)))) → ab(bb(bc(cb(x1)))) (37)
ca(ab(bc(ca(x1)))) → cb(bb(bc(ca(x1)))) (38)
ca(ab(bc(cc(x1)))) → cb(bb(bc(cc(x1)))) (39)
ca(ab(bc(cb(x1)))) → cb(bb(bc(cb(x1)))) (40)
ba(ab(bc(ca(x1)))) → bb(bb(bc(ca(x1)))) (41)
ba(ab(bc(cc(x1)))) → bb(bb(bc(cc(x1)))) (42)
ba(ab(bc(cb(x1)))) → bb(bb(bc(cb(x1)))) (43)
aa(ab(bc(ca(x1)))) → ac(cc(cb(ba(x1)))) (47)
aa(ab(bc(cc(x1)))) → ac(cc(cb(bc(x1)))) (48)
aa(ab(bc(cb(x1)))) → ac(cc(cb(bb(x1)))) (49)
ca(ab(bc(ca(x1)))) → cc(cc(cb(ba(x1)))) (50)
ca(ab(bc(cc(x1)))) → cc(cc(cb(bc(x1)))) (51)
ca(ab(bc(cb(x1)))) → cc(cc(cb(bb(x1)))) (52)
ba(ab(bc(ca(x1)))) → bc(cc(cb(ba(x1)))) (53)
ba(ab(bc(cc(x1)))) → bc(cc(cb(bc(x1)))) (54)
ba(ab(bc(cb(x1)))) → bc(cc(cb(bb(x1)))) (55)
aa(aa(aa(aa(x1)))) → ac(ca(ab(ba(x1)))) (74)
aa(aa(aa(ac(x1)))) → ac(ca(ab(bc(x1)))) (75)
aa(aa(aa(ab(x1)))) → ac(ca(ab(bb(x1)))) (76)
ca(aa(aa(aa(x1)))) → cc(ca(ab(ba(x1)))) (77)
ca(aa(aa(ac(x1)))) → cc(ca(ab(bc(x1)))) (78)
ca(aa(aa(ab(x1)))) → cc(ca(ab(bb(x1)))) (79)
ba(aa(aa(aa(x1)))) → bc(ca(ab(ba(x1)))) (80)
ba(aa(aa(ac(x1)))) → bc(ca(ab(bc(x1)))) (81)
ba(aa(aa(ab(x1)))) → bc(ca(ab(bb(x1)))) (82)

1.1.1.1 Rule Removal

Using the matrix interpretations of dimension 2 with strict dimension 1 over the integers
[aa(x1)] =
0
1
+
2 0
0 0
· x1
[ac(x1)] =
0
0
+
2 1
0 0
· x1
[cb(x1)] =
0
0
+
2 1
0 0
· x1
[ba(x1)] =
0
0
+
2 0
0 0
· x1
[ab(x1)] =
0
1
+
2 0
0 0
· x1
[bc(x1)] =
0
0
+
2 0
0 2
· x1
[bb(x1)] =
0
0
+
2 0
0 0
· x1
[ca(x1)] =
0
0
+
2 0
0 2
· x1
[cc(x1)] =
0
0
+
2 0
0 0
· x1
all of the following rules can be deleted.
cb(bc(ca(aa(x1)))) → ca(ac(cb(ba(x1)))) (68)
cb(bc(ca(ab(x1)))) → ca(ac(cb(bb(x1)))) (70)

1.1.1.1.1 Rule Removal

Using the matrix interpretations of dimension 2 with strict dimension 1 over the integers
[aa(x1)] =
2
0
+
2 0
0 0
· x1
[ac(x1)] =
0
0
+
2 0
0 0
· x1
[cb(x1)] =
1
0
+
2 0
0 0
· x1
[ba(x1)] =
2
0
+
2 0
0 0
· x1
[ab(x1)] =
0
0
+
2 0
0 0
· x1
[bc(x1)] =
0
0
+
2 0
0 0
· x1
[bb(x1)] =
0
0
+
2 0
0 0
· x1
[ca(x1)] =
2
0
+
2 0
0 0
· x1
[cc(x1)] =
0
0
+
2 0
0 0
· x1
all of the following rules can be deleted.
aa(ac(cb(ba(x1)))) → ab(ba(ab(ba(x1)))) (26)
aa(ac(cb(bc(x1)))) → ab(ba(ab(bc(x1)))) (27)
aa(ac(cb(bb(x1)))) → ab(ba(ab(bb(x1)))) (28)
ca(ac(cb(ba(x1)))) → cb(ba(ab(ba(x1)))) (29)
ca(ac(cb(bc(x1)))) → cb(ba(ab(bc(x1)))) (30)
ca(ac(cb(bb(x1)))) → cb(ba(ab(bb(x1)))) (31)
ba(ac(cb(ba(x1)))) → bb(ba(ab(ba(x1)))) (32)
ba(ac(cb(bc(x1)))) → bb(ba(ab(bc(x1)))) (33)
ba(ac(cb(bb(x1)))) → bb(ba(ab(bb(x1)))) (34)
aa(ac(cb(x1))) → aa(ab(bb(x1))) (46)
cb(ba(ac(ca(x1)))) → cc(ca(ac(ca(x1)))) (59)
cb(ba(ac(cc(x1)))) → cc(ca(ac(cc(x1)))) (60)
cb(ba(ac(cb(x1)))) → cc(ca(ac(cb(x1)))) (61)
ab(bc(ca(aa(x1)))) → aa(ac(cb(ba(x1)))) (65)
ab(bc(ca(ac(x1)))) → aa(ac(cb(bc(x1)))) (66)
ab(bc(ca(ab(x1)))) → aa(ac(cb(bb(x1)))) (67)
cb(bc(ca(ac(x1)))) → ca(ac(cb(bc(x1)))) (69)
bb(bc(ca(aa(x1)))) → ba(ac(cb(ba(x1)))) (71)
bb(bc(ca(ac(x1)))) → ba(ac(cb(bc(x1)))) (72)
bb(bc(ca(ab(x1)))) → ba(ac(cb(bb(x1)))) (73)

1.1.1.1.1.1 R is empty

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