| Step | Hyp | Ref | Expression | 
						
							| 1 |  | bnj1175.3 |  | 
						
							| 2 |  | bnj1175.4 |  | 
						
							| 3 |  | bnj1175.5 |  | 
						
							| 4 |  | bnj255 |  | 
						
							| 5 |  | df-bnj17 |  | 
						
							| 6 | 2 4 5 | 3bitr2i |  | 
						
							| 7 | 3 | anbi1i |  | 
						
							| 8 | 6 7 | bitr4i |  | 
						
							| 9 |  | bnj1125 |  | 
						
							| 10 | 2 9 | bnj835 |  | 
						
							| 11 |  | bnj906 |  | 
						
							| 12 | 2 11 | bnj836 |  | 
						
							| 13 |  | bnj1152 |  | 
						
							| 14 | 13 | biimpri |  | 
						
							| 15 | 2 14 | bnj837 |  | 
						
							| 16 | 12 15 | sseldd |  | 
						
							| 17 | 10 16 | sseldd |  | 
						
							| 18 | 8 17 | sylbir |  | 
						
							| 19 | 18 | ex |  |