| Step | Hyp | Ref | Expression | 
						
							| 1 |  | decaddi.1 |  | 
						
							| 2 |  | decaddi.2 |  | 
						
							| 3 |  | decaddi.3 |  | 
						
							| 4 |  | decaddi.4 | Could not format  M = ; A B : No typesetting found for |- M = ; A B with typecode |- | 
						
							| 5 |  | decaddci.5 |  | 
						
							| 6 |  | decsubi.5 |  | 
						
							| 7 |  | 10nn0 |  | 
						
							| 8 | 7 1 | nn0mulcli |  | 
						
							| 9 | 8 | nn0cni |  | 
						
							| 10 | 2 | nn0cni |  | 
						
							| 11 | 3 | nn0cni |  | 
						
							| 12 | 9 10 11 | addsubassi |  | 
						
							| 13 |  | dfdec10 | Could not format  ; A B = ( ( ; 1 0 x. A ) + B ) : No typesetting found for |- ; A B = ( ( ; 1 0 x. A ) + B ) with typecode |- | 
						
							| 14 | 4 13 | eqtri |  | 
						
							| 15 | 14 | oveq1i |  | 
						
							| 16 |  | dfdec10 | Could not format  ; A C = ( ( ; 1 0 x. A ) + C ) : No typesetting found for |- ; A C = ( ( ; 1 0 x. A ) + C ) with typecode |- | 
						
							| 17 | 6 | eqcomi |  | 
						
							| 18 | 17 | oveq2i |  | 
						
							| 19 | 16 18 | eqtri | Could not format  ; A C = ( ( ; 1 0 x. A ) + ( B - N ) ) : No typesetting found for |- ; A C = ( ( ; 1 0 x. A ) + ( B - N ) ) with typecode |- | 
						
							| 20 | 12 15 19 | 3eqtr4i | Could not format  ( M - N ) = ; A C : No typesetting found for |- ( M - N ) = ; A C with typecode |- |