| Step | Hyp | Ref | Expression | 
						
							| 1 |  | difss |  | 
						
							| 2 |  | ssnum |  | 
						
							| 3 | 1 2 | mpan2 |  | 
						
							| 4 |  | isnum3 |  | 
						
							| 5 |  | bren |  | 
						
							| 6 | 4 5 | bitri |  | 
						
							| 7 |  | simp1 |  | 
						
							| 8 |  | simp2 |  | 
						
							| 9 |  | simp3 |  | 
						
							| 10 |  | dmeq |  | 
						
							| 11 | 10 | unieqd |  | 
						
							| 12 | 10 11 | eqeq12d |  | 
						
							| 13 | 10 | eqeq1d |  | 
						
							| 14 |  | rneq |  | 
						
							| 15 | 14 | unieqd |  | 
						
							| 16 | 13 15 | ifbieq2d |  | 
						
							| 17 |  | id |  | 
						
							| 18 | 17 11 | fveq12d |  | 
						
							| 19 | 11 | fveq2d |  | 
						
							| 20 | 19 | sneqd |  | 
						
							| 21 | 18 20 | uneq12d |  | 
						
							| 22 | 21 | eleq1d |  | 
						
							| 23 | 22 20 | ifbieq1d |  | 
						
							| 24 | 18 23 | uneq12d |  | 
						
							| 25 | 12 16 24 | ifbieq12d |  | 
						
							| 26 | 25 | cbvmptv |  | 
						
							| 27 |  | recseq |  | 
						
							| 28 | 26 27 | ax-mp |  | 
						
							| 29 | 7 8 9 28 | ttukeylem7 |  | 
						
							| 30 | 29 | 3expib |  | 
						
							| 31 | 30 | exlimiv |  | 
						
							| 32 | 6 31 | sylbi |  | 
						
							| 33 | 3 32 | syl |  | 
						
							| 34 | 33 | 3impib |  |