| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq1 |  | 
						
							| 2 | 1 | oveq2d |  | 
						
							| 3 |  | df-dp2 | Could not format  _ C A = ( C + ( A / ; 1 0 ) ) : No typesetting found for |- _ C A = ( C + ( A / ; 1 0 ) ) with typecode |- | 
						
							| 4 |  | df-dp2 | Could not format  _ C B = ( C + ( B / ; 1 0 ) ) : No typesetting found for |- _ C B = ( C + ( B / ; 1 0 ) ) with typecode |- | 
						
							| 5 | 2 3 4 | 3eqtr4g | Could not format  ( A = B -> _ C A = _ C B ) : No typesetting found for |- ( A = B -> _ C A = _ C B ) with typecode |- |