| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isssc.1 |  | 
						
							| 2 |  | isssc.2 |  | 
						
							| 3 |  | isssc.3 |  | 
						
							| 4 |  | brssc |  | 
						
							| 5 |  | fndm |  | 
						
							| 6 | 5 | adantl |  | 
						
							| 7 | 2 | adantr |  | 
						
							| 8 | 7 | fndmd |  | 
						
							| 9 | 6 8 | eqtr3d |  | 
						
							| 10 | 9 | dmeqd |  | 
						
							| 11 |  | dmxpid |  | 
						
							| 12 |  | dmxpid |  | 
						
							| 13 | 10 11 12 | 3eqtr3g |  | 
						
							| 14 | 13 | ex |  | 
						
							| 15 |  | id |  | 
						
							| 16 | 15 | sqxpeqd |  | 
						
							| 17 | 16 | fneq2d |  | 
						
							| 18 | 2 17 | syl5ibrcom |  | 
						
							| 19 | 14 18 | impbid |  | 
						
							| 20 | 19 | anbi1d |  | 
						
							| 21 | 20 | exbidv |  | 
						
							| 22 | 4 21 | bitrid |  | 
						
							| 23 |  | pweq |  | 
						
							| 24 | 23 | rexeqdv |  | 
						
							| 25 | 24 | ceqsexgv |  | 
						
							| 26 | 3 25 | syl |  | 
						
							| 27 | 22 26 | bitrd |  | 
						
							| 28 |  | df-rex |  | 
						
							| 29 |  | 3anass |  | 
						
							| 30 |  | elixp2 |  | 
						
							| 31 |  | vex |  | 
						
							| 32 | 31 31 | xpex |  | 
						
							| 33 |  | fnex |  | 
						
							| 34 | 32 33 | mpan2 |  | 
						
							| 35 | 34 | adantr |  | 
						
							| 36 | 35 | pm4.71ri |  | 
						
							| 37 | 29 30 36 | 3bitr4i |  | 
						
							| 38 |  | fndm |  | 
						
							| 39 | 38 | adantl |  | 
						
							| 40 | 1 | adantr |  | 
						
							| 41 | 40 | fndmd |  | 
						
							| 42 | 39 41 | eqtr3d |  | 
						
							| 43 | 42 | dmeqd |  | 
						
							| 44 |  | dmxpid |  | 
						
							| 45 |  | dmxpid |  | 
						
							| 46 | 43 44 45 | 3eqtr3g |  | 
						
							| 47 | 46 | ex |  | 
						
							| 48 |  | id |  | 
						
							| 49 | 48 | sqxpeqd |  | 
						
							| 50 | 49 | fneq2d |  | 
						
							| 51 | 1 50 | syl5ibrcom |  | 
						
							| 52 | 47 51 | impbid |  | 
						
							| 53 | 52 | anbi1d |  | 
						
							| 54 | 37 53 | bitrid |  | 
						
							| 55 | 54 | anbi2d |  | 
						
							| 56 |  | an12 |  | 
						
							| 57 | 55 56 | bitrdi |  | 
						
							| 58 | 57 | exbidv |  | 
						
							| 59 | 28 58 | bitrid |  | 
						
							| 60 |  | exsimpl |  | 
						
							| 61 |  | isset |  | 
						
							| 62 | 60 61 | sylibr |  | 
						
							| 63 | 62 | a1i |  | 
						
							| 64 |  | ssexg |  | 
						
							| 65 | 64 | expcom |  | 
						
							| 66 | 3 65 | syl |  | 
						
							| 67 | 66 | adantrd |  | 
						
							| 68 | 31 | elpw |  | 
						
							| 69 |  | sseq1 |  | 
						
							| 70 | 68 69 | bitrid |  | 
						
							| 71 | 49 | raleqdv |  | 
						
							| 72 |  | fvex |  | 
						
							| 73 | 72 | elpw |  | 
						
							| 74 |  | fveq2 |  | 
						
							| 75 |  | df-ov |  | 
						
							| 76 | 74 75 | eqtr4di |  | 
						
							| 77 |  | fveq2 |  | 
						
							| 78 |  | df-ov |  | 
						
							| 79 | 77 78 | eqtr4di |  | 
						
							| 80 | 76 79 | sseq12d |  | 
						
							| 81 | 73 80 | bitrid |  | 
						
							| 82 | 81 | ralxp |  | 
						
							| 83 | 71 82 | bitrdi |  | 
						
							| 84 | 70 83 | anbi12d |  | 
						
							| 85 | 84 | ceqsexgv |  | 
						
							| 86 | 85 | a1i |  | 
						
							| 87 | 63 67 86 | pm5.21ndd |  | 
						
							| 88 | 27 59 87 | 3bitrd |  |