Certification Problem
Input (TPDB SRS_Standard/Zantema_04/z127)
The rewrite relation of the following TRS is considered.
|
a(a(a(x1))) |
→ |
a(b(b(x1))) |
(1) |
|
b(a(b(x1))) |
→ |
a(b(a(x1))) |
(2) |
Property / Task
Prove or disprove termination.Answer / Result
No.Proof (by ttt2 @ termCOMP 2023)
1 Loop
The following loop proves nontermination.
| t0
|
= |
a(a(a(a(b(a(x631)))))) |
|
→
|
a(b(b(a(b(a(x631)))))) |
|
→
|
a(b(a(b(a(a(x631)))))) |
|
→
|
a(a(b(a(a(a(x631)))))) |
|
→
|
a(a(b(a(b(b(x631)))))) |
|
→
|
a(a(a(b(a(b(x631)))))) |
|
→
|
a(a(a(a(b(a(x631)))))) |
|
= |
t6
|
where t6 =
t0σ
and
σ =
{x631/x631}