Certification Problem                    
                
Input (COPS 74)
We consider the TRS containing the following rules:
| a | 
→ | 
c | 
(1) | 
| b | 
→ | 
c | 
(2) | 
| 
f(a,b) | 
→ | 
d | 
(3) | 
| 
f(x,c) | 
→ | 
f(c,c) | 
(4) | 
| 
f(c,x) | 
→ | 
f(c,c) | 
(5) | 
| d | 
→ | 
f(a,c) | 
(6) | 
| d | 
→ | 
f(c,b) | 
(7) | 
The underlying signature is as follows:
{a/0, c/0, b/0, f/2, d/0}Property / Task
Prove or disprove confluence.Answer / Result
Yes.Proof (by ACP @ CoCo 2020)
1 Strongly closed
        Confluence is proven since the TRS is strongly closed. 
        
        The joins can be performed using 
        3
        step(s).