Certification Problem
Input (COPS 330)
The rewrite relation of the following conditional TRS is considered.
|
pin(x) |
→ |
pout(g(x)) |
|
pin(x) |
→ |
pout(f(y)) |
| pin(x) ≈ pout(g(y)) |
Property / Task
Prove or disprove confluence.Answer / Result
No.Proof (by ConCon @ CoCo 2020)
1 Non-Joinable Fork
The system is not confluent due to the following forking derivations.
|
pin(__N4) |
→*
|
pout(g(__N4)) |
|
pin(__N4) |
→*
|
pout(f(__N4)) |
The two resulting terms cannot be joined for the following reason:
- The terms are distinct normal forms.