| Step | Hyp | Ref | Expression | 
						
							| 1 |  | brinxp |  | 
						
							| 2 | 1 | anidms |  | 
						
							| 3 | 2 | ad2antrr |  | 
						
							| 4 | 3 | notbid |  | 
						
							| 5 |  | brinxp |  | 
						
							| 6 | 5 | adantr |  | 
						
							| 7 |  | brinxp |  | 
						
							| 8 | 7 | adantll |  | 
						
							| 9 | 6 8 | anbi12d |  | 
						
							| 10 |  | brinxp |  | 
						
							| 11 | 10 | adantlr |  | 
						
							| 12 | 9 11 | imbi12d |  | 
						
							| 13 | 4 12 | anbi12d |  | 
						
							| 14 | 13 | ralbidva |  | 
						
							| 15 | 14 | ralbidva |  | 
						
							| 16 | 15 | ralbiia |  | 
						
							| 17 |  | df-po |  | 
						
							| 18 |  | df-po |  | 
						
							| 19 | 16 17 18 | 3bitr4i |  |