| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dfon2lem4.1 |  | 
						
							| 2 |  | dfon2lem4.2 |  | 
						
							| 3 |  | inss1 |  | 
						
							| 4 | 3 | sseli |  | 
						
							| 5 |  | dfon2lem3 |  | 
						
							| 6 | 1 5 | ax-mp |  | 
						
							| 7 | 6 | simprd |  | 
						
							| 8 |  | eleq1 |  | 
						
							| 9 |  | eleq2 |  | 
						
							| 10 | 8 9 | bitrd |  | 
						
							| 11 | 10 | notbid |  | 
						
							| 12 | 11 | rspccv |  | 
						
							| 13 | 7 12 | syl |  | 
						
							| 14 | 13 | adantr |  | 
						
							| 15 | 4 14 | syl5 |  | 
						
							| 16 | 15 | pm2.01d |  | 
						
							| 17 |  | elin |  | 
						
							| 18 | 16 17 | sylnib |  | 
						
							| 19 | 6 | simpld |  | 
						
							| 20 |  | dfon2lem3 |  | 
						
							| 21 | 2 20 | ax-mp |  | 
						
							| 22 | 21 | simpld |  | 
						
							| 23 |  | trin |  | 
						
							| 24 | 19 22 23 | syl2an |  | 
						
							| 25 | 1 | inex1 |  | 
						
							| 26 |  | psseq1 |  | 
						
							| 27 |  | treq |  | 
						
							| 28 | 26 27 | anbi12d |  | 
						
							| 29 |  | eleq1 |  | 
						
							| 30 | 28 29 | imbi12d |  | 
						
							| 31 | 25 30 | spcv |  | 
						
							| 32 | 31 | adantr |  | 
						
							| 33 | 24 32 | mpan2d |  | 
						
							| 34 |  | psseq1 |  | 
						
							| 35 |  | treq |  | 
						
							| 36 | 34 35 | anbi12d |  | 
						
							| 37 |  | eleq1 |  | 
						
							| 38 | 36 37 | imbi12d |  | 
						
							| 39 | 25 38 | spcv |  | 
						
							| 40 | 39 | adantl |  | 
						
							| 41 | 24 40 | mpan2d |  | 
						
							| 42 | 33 41 | anim12d |  | 
						
							| 43 | 18 42 | mtod |  | 
						
							| 44 |  | ianor |  | 
						
							| 45 | 43 44 | sylib |  | 
						
							| 46 |  | sspss |  | 
						
							| 47 | 3 46 | mpbi |  | 
						
							| 48 |  | inss2 |  | 
						
							| 49 |  | sspss |  | 
						
							| 50 | 48 49 | mpbi |  | 
						
							| 51 |  | orel1 |  | 
						
							| 52 |  | orc |  | 
						
							| 53 | 51 52 | syl6 |  | 
						
							| 54 |  | orel1 |  | 
						
							| 55 |  | olc |  | 
						
							| 56 | 54 55 | syl6 |  | 
						
							| 57 | 53 56 | jaoa |  | 
						
							| 58 | 47 50 57 | mp2ani |  | 
						
							| 59 | 45 58 | syl |  | 
						
							| 60 |  | dfss2 |  | 
						
							| 61 |  | sseqin2 |  | 
						
							| 62 | 60 61 | orbi12i |  | 
						
							| 63 | 59 62 | sylibr |  |