| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 4at.l |  | 
						
							| 2 |  | 4at.j |  | 
						
							| 3 |  | 4at.a |  | 
						
							| 4 |  | simp11 |  | 
						
							| 5 |  | simp12 |  | 
						
							| 6 |  | simp13 |  | 
						
							| 7 | 4 | hllatd |  | 
						
							| 8 |  | simp21 |  | 
						
							| 9 |  | simp22 |  | 
						
							| 10 |  | eqid |  | 
						
							| 11 | 10 2 3 | hlatjcl |  | 
						
							| 12 | 4 8 9 11 | syl3anc |  | 
						
							| 13 |  | simp23 |  | 
						
							| 14 | 10 3 | atbase |  | 
						
							| 15 | 13 14 | syl |  | 
						
							| 16 | 10 2 | latjcl |  | 
						
							| 17 | 7 12 15 16 | syl3anc |  | 
						
							| 18 |  | simp3 |  | 
						
							| 19 | 10 1 2 3 | hlexchb2 |  | 
						
							| 20 | 4 5 6 17 18 19 | syl131anc |  | 
						
							| 21 | 1 2 3 | 4atlem4a |  | 
						
							| 22 | 4 6 8 9 13 21 | syl32anc |  | 
						
							| 23 | 22 | breq2d |  | 
						
							| 24 | 1 2 3 | 4atlem4a |  | 
						
							| 25 | 4 5 8 9 13 24 | syl32anc |  | 
						
							| 26 | 25 22 | eqeq12d |  | 
						
							| 27 | 20 23 26 | 3bitr4d |  |