| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dp20u.1 |  | 
						
							| 2 |  | df-dp2 | Could not format  _ A 0 = ( A + ( 0 / ; 1 0 ) ) : No typesetting found for |- _ A 0 = ( A + ( 0 / ; 1 0 ) ) with typecode |- | 
						
							| 3 |  | 10nn0 |  | 
						
							| 4 | 3 | nn0rei |  | 
						
							| 5 | 4 | recni |  | 
						
							| 6 |  | 0re |  | 
						
							| 7 |  | 10pos |  | 
						
							| 8 | 6 7 | gtneii |  | 
						
							| 9 |  | div0 |  | 
						
							| 10 | 5 8 9 | mp2an |  | 
						
							| 11 | 10 | oveq2i |  | 
						
							| 12 | 1 | nn0cni |  | 
						
							| 13 | 12 | addridi |  | 
						
							| 14 | 2 11 13 | 3eqtri | Could not format  _ A 0 = A : No typesetting found for |- _ A 0 = A with typecode |- |