| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ltrnset.l |  | 
						
							| 2 |  | ltrnset.j |  | 
						
							| 3 |  | ltrnset.m |  | 
						
							| 4 |  | ltrnset.a |  | 
						
							| 5 |  | ltrnset.h |  | 
						
							| 6 |  | ltrnset.d |  | 
						
							| 7 |  | ltrnset.t |  | 
						
							| 8 | 1 2 3 4 5 6 7 | isltrn |  | 
						
							| 9 |  | 3simpa |  | 
						
							| 10 | 9 | imim1i |  | 
						
							| 11 |  | 3anass |  | 
						
							| 12 |  | 3anrot |  | 
						
							| 13 |  | df-ne |  | 
						
							| 14 | 13 | anbi1i |  | 
						
							| 15 | 11 12 14 | 3bitr3i |  | 
						
							| 16 | 15 | imbi1i |  | 
						
							| 17 |  | impexp |  | 
						
							| 18 | 16 17 | bitri |  | 
						
							| 19 |  | id |  | 
						
							| 20 |  | fveq2 |  | 
						
							| 21 | 19 20 | oveq12d |  | 
						
							| 22 | 21 | oveq1d |  | 
						
							| 23 | 22 | a1d |  | 
						
							| 24 |  | pm2.61 |  | 
						
							| 25 | 23 24 | ax-mp |  | 
						
							| 26 | 18 25 | sylbi |  | 
						
							| 27 | 10 26 | impbii |  | 
						
							| 28 | 27 | 2ralbii |  | 
						
							| 29 | 28 | anbi2i |  | 
						
							| 30 | 8 29 | bitrdi |  |