| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 3at.l |  | 
						
							| 2 |  | 3at.j |  | 
						
							| 3 |  | 3at.a |  | 
						
							| 4 |  | simpl1 |  | 
						
							| 5 |  | simpl2l |  | 
						
							| 6 |  | simpl2r |  | 
						
							| 7 |  | simpr |  | 
						
							| 8 |  | simpl3 |  | 
						
							| 9 | 1 2 3 | 3atlem6 |  | 
						
							| 10 | 4 5 6 7 8 9 | syl131anc |  | 
						
							| 11 |  | simpl1 |  | 
						
							| 12 |  | simpl2l |  | 
						
							| 13 |  | simpl2r |  | 
						
							| 14 |  | simpr |  | 
						
							| 15 |  | simpl3 |  | 
						
							| 16 | 1 2 3 | 3atlem5 |  | 
						
							| 17 | 11 12 13 14 15 16 | syl131anc |  | 
						
							| 18 | 10 17 | pm2.61dan |  |