| Step | Hyp | Ref | Expression | 
						
							| 1 |  | satfv0.s |  | 
						
							| 2 |  | peano1 |  | 
						
							| 3 |  | elelsuc |  | 
						
							| 4 | 2 3 | mp1i |  | 
						
							| 5 | 1 | satfvsucom |  | 
						
							| 6 | 4 5 | mpd3an3 |  | 
						
							| 7 |  | goelel3xp |  | 
						
							| 8 |  | eleq1 |  | 
						
							| 9 | 7 8 | syl5ibrcom |  | 
						
							| 10 | 9 | adantrd |  | 
						
							| 11 | 10 | pm4.71d |  | 
						
							| 12 | 11 | 2rexbiia |  | 
						
							| 13 |  | r19.41vv |  | 
						
							| 14 |  | ancom |  | 
						
							| 15 | 12 13 14 | 3bitri |  | 
						
							| 16 | 15 | opabbii |  | 
						
							| 17 |  | omex |  | 
						
							| 18 | 17 17 | xpex |  | 
						
							| 19 |  | xpexg |  | 
						
							| 20 |  | oveq1 |  | 
						
							| 21 | 20 | eqeq2d |  | 
						
							| 22 |  | fveq2 |  | 
						
							| 23 | 22 | breq1d |  | 
						
							| 24 | 23 | rabbidv |  | 
						
							| 25 | 24 | eqeq2d |  | 
						
							| 26 | 21 25 | anbi12d |  | 
						
							| 27 |  | oveq2 |  | 
						
							| 28 | 27 | eqeq2d |  | 
						
							| 29 |  | fveq2 |  | 
						
							| 30 | 29 | breq2d |  | 
						
							| 31 | 30 | rabbidv |  | 
						
							| 32 | 31 | eqeq2d |  | 
						
							| 33 | 28 32 | anbi12d |  | 
						
							| 34 | 26 33 | cbvrex2vw |  | 
						
							| 35 |  | eqeq1 |  | 
						
							| 36 | 35 | adantl |  | 
						
							| 37 |  | goeleq12bg |  | 
						
							| 38 | 22 | eqcomd |  | 
						
							| 39 | 29 | eqcomd |  | 
						
							| 40 | 38 39 | breqan12d |  | 
						
							| 41 | 40 | rabbidv |  | 
						
							| 42 | 37 41 | biimtrdi |  | 
						
							| 43 | 42 | imp |  | 
						
							| 44 |  | eqeq12 |  | 
						
							| 45 | 43 44 | syl5ibrcom |  | 
						
							| 46 | 45 | exp4b |  | 
						
							| 47 | 46 | adantr |  | 
						
							| 48 | 36 47 | sylbid |  | 
						
							| 49 | 48 | impd |  | 
						
							| 50 | 49 | com23 |  | 
						
							| 51 | 50 | expimpd |  | 
						
							| 52 | 51 | rexlimdvva |  | 
						
							| 53 | 52 | com23 |  | 
						
							| 54 | 53 | rexlimivv |  | 
						
							| 55 | 34 54 | sylbi |  | 
						
							| 56 | 55 | imp |  | 
						
							| 57 | 56 | gen2 |  | 
						
							| 58 |  | eqeq1 |  | 
						
							| 59 | 58 | anbi2d |  | 
						
							| 60 | 59 | 2rexbidv |  | 
						
							| 61 | 60 | mo4 |  | 
						
							| 62 | 57 61 | mpbir |  | 
						
							| 63 |  | moabex |  | 
						
							| 64 | 62 63 | mp1i |  | 
						
							| 65 | 19 64 | opabex3d |  | 
						
							| 66 | 17 18 65 | mp2an |  | 
						
							| 67 | 16 66 | eqeltri |  | 
						
							| 68 | 67 | rdg0 |  | 
						
							| 69 | 6 68 | eqtrdi |  |