| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 3at.l |  | 
						
							| 2 |  | 3at.j |  | 
						
							| 3 |  | 3at.a |  | 
						
							| 4 |  | simpl1 |  | 
						
							| 5 |  | simpl21 |  | 
						
							| 6 |  | simpl22 |  | 
						
							| 7 |  | simpr |  | 
						
							| 8 | 6 7 | jca |  | 
						
							| 9 |  | simpl23 |  | 
						
							| 10 |  | simpl3 |  | 
						
							| 11 | 1 2 3 | 3atlem2 |  | 
						
							| 12 | 4 5 8 9 10 11 | syl131anc |  | 
						
							| 13 |  | simpl1 |  | 
						
							| 14 |  | simpl21 |  | 
						
							| 15 |  | simpr |  | 
						
							| 16 |  | simpl23 |  | 
						
							| 17 |  | simpl3 |  | 
						
							| 18 | 1 2 3 | 3atlem1 |  | 
						
							| 19 | 13 14 15 16 17 18 | syl131anc |  | 
						
							| 20 | 12 19 | pm2.61dan |  |