We consider the TRS containing the following rules:
| +(0,y) | → | y | (1) | 
| +(x,s(y)) | → | s(+(y,x)) | (2) | 
| +(x,y) | → | +(y,x) | (3) | 
The underlying signature is as follows:
{+/2, 0/0, s/1}To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:
| +(x,y) | → | +(y,x) | (3) | 
| +(x,s(y)) | → | s(+(y,x)) | (2) | 
| +(0,y) | → | y | (1) | 
| s(+(x34,0)) | → | s(x34) | (4) | 
| +(y,0) | → | y | (5) | 
| +(s(y),x) | → | s(+(y,x)) | (6) | 
| s(+(y,0)) | → | s(y) | (7) | 
| +(s(x32),x) | → | s(+(x32,x)) | (8) | 
All redundant rules that were added or removed can be simulated in 2 steps .