Certification Problem
Input (TPDB TRS_Standard/Transformed_CSR_04/Ex24_Luc06_FR)
The rewrite relation of the following TRS is considered.
f(n__b,X,n__c) |
→ |
f(X,c,X) |
(1) |
c |
→ |
b |
(2) |
b |
→ |
n__b |
(3) |
c |
→ |
n__c |
(4) |
activate(n__b) |
→ |
b |
(5) |
activate(n__c) |
→ |
c |
(6) |
activate(X) |
→ |
X |
(7) |
Property / Task
Prove or disprove termination.Answer / Result
No.Proof (by ttt2 @ termCOMP 2023)
1 Loop
The following loop proves nontermination.
t0
|
= |
f(c,c,c) |
|
→
|
f(c,c,n__c) |
|
→
|
f(b,c,n__c) |
|
→
|
f(n__b,c,n__c) |
|
→
|
f(c,c,c) |
|
= |
t4
|
where t4 =
t0