| Step | Hyp | Ref | Expression | 
						
							| 1 |  | islln3.b |  | 
						
							| 2 |  | islln3.j |  | 
						
							| 3 |  | islln3.a |  | 
						
							| 4 |  | islln3.n |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 | 1 5 3 4 | islln4 |  | 
						
							| 7 |  | simpll |  | 
						
							| 8 | 1 3 | atbase |  | 
						
							| 9 | 8 | adantl |  | 
						
							| 10 |  | simplr |  | 
						
							| 11 |  | eqid |  | 
						
							| 12 | 1 11 2 5 3 | cvrval3 |  | 
						
							| 13 | 7 9 10 12 | syl3anc |  | 
						
							| 14 |  | hlatl |  | 
						
							| 15 | 14 | ad3antrrr |  | 
						
							| 16 |  | simpr |  | 
						
							| 17 |  | simplr |  | 
						
							| 18 | 11 3 | atncmp |  | 
						
							| 19 | 15 16 17 18 | syl3anc |  | 
						
							| 20 |  | necom |  | 
						
							| 21 | 19 20 | bitrdi |  | 
						
							| 22 |  | eqcom |  | 
						
							| 23 | 22 | a1i |  | 
						
							| 24 | 21 23 | anbi12d |  | 
						
							| 25 | 24 | rexbidva |  | 
						
							| 26 | 13 25 | bitrd |  | 
						
							| 27 | 26 | rexbidva |  | 
						
							| 28 | 6 27 | bitrd |  |