Certification Problem
Input (TPDB SRS_Relative/Waldmann_19/random-137)
The rewrite relation of the following TRS is considered.
|
a(c(a(x1))) |
→ |
b(a(c(x1))) |
(1) |
|
a(c(c(x1))) |
→ |
a(b(b(x1))) |
(2) |
|
c(a(a(x1))) |
→ |
a(a(a(x1))) |
(3) |
|
b(c(c(x1))) |
→ |
a(c(a(x1))) |
(4) |
|
b(a(a(x1))) |
→ |
b(c(b(x1))) |
(5) |
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(c(c(x1))) |
→ |
a(b(b(x1))) |
(2) |
|
b(a(a(x1))) |
→ |
b(c(b(x1))) |
(5) |
|
a(a(c(a(x1)))) |
→ |
a(b(a(c(x1)))) |
(6) |
|
c(a(c(a(x1)))) |
→ |
c(b(a(c(x1)))) |
(7) |
|
b(a(c(a(x1)))) |
→ |
b(b(a(c(x1)))) |
(8) |
|
a(c(a(a(x1)))) |
→ |
a(a(a(a(x1)))) |
(9) |
|
c(c(a(a(x1)))) |
→ |
c(a(a(a(x1)))) |
(10) |
|
b(c(a(a(x1)))) |
→ |
b(a(a(a(x1)))) |
(11) |
|
a(b(c(c(x1)))) |
→ |
a(a(c(a(x1)))) |
(12) |
|
c(b(c(c(x1)))) |
→ |
c(a(c(a(x1)))) |
(13) |
|
b(b(c(c(x1)))) |
→ |
b(a(c(a(x1)))) |
(14) |
1.1 Semantic Labeling
Root-labeling is applied.
We obtain the labeled TRS
|
ac(cc(ca(x1))) |
→ |
ab(bb(ba(x1))) |
(15) |
|
ac(cc(cc(x1))) |
→ |
ab(bb(bc(x1))) |
(16) |
|
ac(cc(cb(x1))) |
→ |
ab(bb(bb(x1))) |
(17) |
|
ba(aa(aa(x1))) |
→ |
bc(cb(ba(x1))) |
(18) |
|
ba(aa(ac(x1))) |
→ |
bc(cb(bc(x1))) |
(19) |
|
ba(aa(ab(x1))) |
→ |
bc(cb(bb(x1))) |
(20) |
|
aa(ac(ca(aa(x1)))) |
→ |
ab(ba(ac(ca(x1)))) |
(21) |
|
aa(ac(ca(ac(x1)))) |
→ |
ab(ba(ac(cc(x1)))) |
(22) |
|
aa(ac(ca(ab(x1)))) |
→ |
ab(ba(ac(cb(x1)))) |
(23) |
|
ca(ac(ca(aa(x1)))) |
→ |
cb(ba(ac(ca(x1)))) |
(24) |
|
ca(ac(ca(ac(x1)))) |
→ |
cb(ba(ac(cc(x1)))) |
(25) |
|
ca(ac(ca(ab(x1)))) |
→ |
cb(ba(ac(cb(x1)))) |
(26) |
|
ba(ac(ca(aa(x1)))) |
→ |
bb(ba(ac(ca(x1)))) |
(27) |
|
ba(ac(ca(ac(x1)))) |
→ |
bb(ba(ac(cc(x1)))) |
(28) |
|
ba(ac(ca(ab(x1)))) |
→ |
bb(ba(ac(cb(x1)))) |
(29) |
|
ac(ca(aa(aa(x1)))) |
→ |
aa(aa(aa(aa(x1)))) |
(30) |
|
ac(ca(aa(ac(x1)))) |
→ |
aa(aa(aa(ac(x1)))) |
(31) |
|
ac(ca(aa(ab(x1)))) |
→ |
aa(aa(aa(ab(x1)))) |
(32) |
|
cc(ca(aa(aa(x1)))) |
→ |
ca(aa(aa(aa(x1)))) |
(33) |
|
cc(ca(aa(ac(x1)))) |
→ |
ca(aa(aa(ac(x1)))) |
(34) |
|
cc(ca(aa(ab(x1)))) |
→ |
ca(aa(aa(ab(x1)))) |
(35) |
|
bc(ca(aa(aa(x1)))) |
→ |
ba(aa(aa(aa(x1)))) |
(36) |
|
bc(ca(aa(ac(x1)))) |
→ |
ba(aa(aa(ac(x1)))) |
(37) |
|
bc(ca(aa(ab(x1)))) |
→ |
ba(aa(aa(ab(x1)))) |
(38) |
|
ab(bc(cc(ca(x1)))) |
→ |
aa(ac(ca(aa(x1)))) |
(39) |
|
ab(bc(cc(cc(x1)))) |
→ |
aa(ac(ca(ac(x1)))) |
(40) |
|
ab(bc(cc(cb(x1)))) |
→ |
aa(ac(ca(ab(x1)))) |
(41) |
|
cb(bc(cc(ca(x1)))) |
→ |
ca(ac(ca(aa(x1)))) |
(42) |
|
cb(bc(cc(cc(x1)))) |
→ |
ca(ac(ca(ac(x1)))) |
(43) |
|
cb(bc(cc(cb(x1)))) |
→ |
ca(ac(ca(ab(x1)))) |
(44) |
|
bb(bc(cc(ca(x1)))) |
→ |
ba(ac(ca(aa(x1)))) |
(45) |
|
bb(bc(cc(cc(x1)))) |
→ |
ba(ac(ca(ac(x1)))) |
(46) |
|
bb(bc(cc(cb(x1)))) |
→ |
ba(ac(ca(ab(x1)))) |
(47) |
1.1.1 Rule Removal
Using the
linear polynomial interpretation over the naturals
| [ac(x1)] |
= |
1 · x1
|
| [cc(x1)] |
= |
1 · x1 + 9 |
| [ca(x1)] |
= |
1 · x1 + 10 |
| [ab(x1)] |
= |
1 · x1 + 2 |
| [bb(x1)] |
= |
1 · x1
|
| [ba(x1)] |
= |
1 · x1 + 3 |
| [bc(x1)] |
= |
1 · x1
|
| [cb(x1)] |
= |
1 · x1 + 7 |
| [aa(x1)] |
= |
1 · x1 + 5 |
all of the following rules can be deleted.
|
ac(cc(ca(x1))) |
→ |
ab(bb(ba(x1))) |
(15) |
|
ac(cc(cc(x1))) |
→ |
ab(bb(bc(x1))) |
(16) |
|
ac(cc(cb(x1))) |
→ |
ab(bb(bb(x1))) |
(17) |
|
ba(aa(aa(x1))) |
→ |
bc(cb(ba(x1))) |
(18) |
|
ba(aa(ac(x1))) |
→ |
bc(cb(bc(x1))) |
(19) |
|
ba(aa(ab(x1))) |
→ |
bc(cb(bb(x1))) |
(20) |
|
aa(ac(ca(aa(x1)))) |
→ |
ab(ba(ac(ca(x1)))) |
(21) |
|
aa(ac(ca(ac(x1)))) |
→ |
ab(ba(ac(cc(x1)))) |
(22) |
|
aa(ac(ca(ab(x1)))) |
→ |
ab(ba(ac(cb(x1)))) |
(23) |
|
ca(ac(ca(aa(x1)))) |
→ |
cb(ba(ac(ca(x1)))) |
(24) |
|
ca(ac(ca(ac(x1)))) |
→ |
cb(ba(ac(cc(x1)))) |
(25) |
|
ca(ac(ca(ab(x1)))) |
→ |
cb(ba(ac(cb(x1)))) |
(26) |
|
ba(ac(ca(aa(x1)))) |
→ |
bb(ba(ac(ca(x1)))) |
(27) |
|
ba(ac(ca(ac(x1)))) |
→ |
bb(ba(ac(cc(x1)))) |
(28) |
|
ba(ac(ca(ab(x1)))) |
→ |
bb(ba(ac(cb(x1)))) |
(29) |
|
cc(ca(aa(aa(x1)))) |
→ |
ca(aa(aa(aa(x1)))) |
(33) |
|
cc(ca(aa(ac(x1)))) |
→ |
ca(aa(aa(ac(x1)))) |
(34) |
|
cc(ca(aa(ab(x1)))) |
→ |
ca(aa(aa(ab(x1)))) |
(35) |
|
bc(ca(aa(aa(x1)))) |
→ |
ba(aa(aa(aa(x1)))) |
(36) |
|
bc(ca(aa(ac(x1)))) |
→ |
ba(aa(aa(ac(x1)))) |
(37) |
|
bc(ca(aa(ab(x1)))) |
→ |
ba(aa(aa(ab(x1)))) |
(38) |
|
ab(bc(cc(ca(x1)))) |
→ |
aa(ac(ca(aa(x1)))) |
(39) |
|
ab(bc(cc(cc(x1)))) |
→ |
aa(ac(ca(ac(x1)))) |
(40) |
|
ab(bc(cc(cb(x1)))) |
→ |
aa(ac(ca(ab(x1)))) |
(41) |
|
cb(bc(cc(ca(x1)))) |
→ |
ca(ac(ca(aa(x1)))) |
(42) |
|
cb(bc(cc(cc(x1)))) |
→ |
ca(ac(ca(ac(x1)))) |
(43) |
|
cb(bc(cc(cb(x1)))) |
→ |
ca(ac(ca(ab(x1)))) |
(44) |
|
bb(bc(cc(ca(x1)))) |
→ |
ba(ac(ca(aa(x1)))) |
(45) |
|
bb(bc(cc(cc(x1)))) |
→ |
ba(ac(ca(ac(x1)))) |
(46) |
|
bb(bc(cc(cb(x1)))) |
→ |
ba(ac(ca(ab(x1)))) |
(47) |
1.1.1.1 Rule Removal
Using the
linear polynomial interpretation over the naturals
| [ac(x1)] |
= |
1 · x1
|
| [ca(x1)] |
= |
1 · x1 + 1 |
| [aa(x1)] |
= |
1 · x1
|
| [ab(x1)] |
= |
1 · x1
|
all of the following rules can be deleted.
|
ac(ca(aa(aa(x1)))) |
→ |
aa(aa(aa(aa(x1)))) |
(30) |
|
ac(ca(aa(ac(x1)))) |
→ |
aa(aa(aa(ac(x1)))) |
(31) |
|
ac(ca(aa(ab(x1)))) |
→ |
aa(aa(aa(ab(x1)))) |
(32) |
1.1.1.1.1 R is empty
There are no rules in the TRS. Hence, it is terminating.