| Step | Hyp | Ref | Expression | 
						
							| 1 |  | bcth.2 |  | 
						
							| 2 |  | bcthlem.4 |  | 
						
							| 3 |  | bcthlem.5 |  | 
						
							| 4 |  | opabssxp |  | 
						
							| 5 |  | elfvdm |  | 
						
							| 6 | 2 5 | syl |  | 
						
							| 7 |  | reex |  | 
						
							| 8 |  | rpssre |  | 
						
							| 9 | 7 8 | ssexi |  | 
						
							| 10 |  | xpexg |  | 
						
							| 11 | 6 9 10 | sylancl |  | 
						
							| 12 |  | ssexg |  | 
						
							| 13 | 4 11 12 | sylancr |  | 
						
							| 14 |  | oveq2 |  | 
						
							| 15 | 14 | breq2d |  | 
						
							| 16 |  | fveq2 |  | 
						
							| 17 | 16 | difeq2d |  | 
						
							| 18 | 17 | sseq2d |  | 
						
							| 19 | 15 18 | anbi12d |  | 
						
							| 20 | 19 | anbi2d |  | 
						
							| 21 | 20 | opabbidv |  | 
						
							| 22 |  | fveq2 |  | 
						
							| 23 | 22 | difeq1d |  | 
						
							| 24 | 23 | sseq2d |  | 
						
							| 25 | 24 | anbi2d |  | 
						
							| 26 | 25 | anbi2d |  | 
						
							| 27 | 26 | opabbidv |  | 
						
							| 28 | 21 27 3 | ovmpog |  | 
						
							| 29 | 13 28 | syl3an3 |  | 
						
							| 30 | 29 | 3expa |  | 
						
							| 31 | 30 | ancoms |  | 
						
							| 32 | 31 | eleq2d |  | 
						
							| 33 | 4 | sseli |  | 
						
							| 34 |  | simp1 |  | 
						
							| 35 |  | 1st2nd2 |  | 
						
							| 36 | 35 | eleq1d |  | 
						
							| 37 |  | fvex |  | 
						
							| 38 |  | fvex |  | 
						
							| 39 |  | eleq1 |  | 
						
							| 40 |  | eleq1 |  | 
						
							| 41 | 39 40 | bi2anan9 |  | 
						
							| 42 |  | simpr |  | 
						
							| 43 | 42 | breq1d |  | 
						
							| 44 |  | oveq12 |  | 
						
							| 45 | 44 | fveq2d |  | 
						
							| 46 | 45 | sseq1d |  | 
						
							| 47 | 43 46 | anbi12d |  | 
						
							| 48 | 41 47 | anbi12d |  | 
						
							| 49 | 37 38 48 | opelopaba |  | 
						
							| 50 | 36 49 | bitrdi |  | 
						
							| 51 | 35 | eleq1d |  | 
						
							| 52 |  | opelxp |  | 
						
							| 53 | 51 52 | bitr2di |  | 
						
							| 54 |  | df-ov |  | 
						
							| 55 | 35 | fveq2d |  | 
						
							| 56 | 54 55 | eqtr4id |  | 
						
							| 57 | 56 | fveq2d |  | 
						
							| 58 | 57 | sseq1d |  | 
						
							| 59 | 58 | anbi2d |  | 
						
							| 60 | 53 59 | anbi12d |  | 
						
							| 61 |  | 3anass |  | 
						
							| 62 | 60 61 | bitr4di |  | 
						
							| 63 | 50 62 | bitrd |  | 
						
							| 64 | 33 34 63 | pm5.21nii |  | 
						
							| 65 | 32 64 | bitrdi |  |