| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pwidg |  |-  ( B e. V -> B e. ~P B ) | 
						
							| 2 | 1 | ad2antrr |  |-  ( ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) /\ ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) ) -> B e. ~P B ) | 
						
							| 3 |  | 0elpw |  |-  (/) e. ~P B | 
						
							| 4 | 3 | a1i |  |-  ( ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) /\ ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) ) -> (/) e. ~P B ) | 
						
							| 5 |  | simprr |  |-  ( ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) /\ ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) ) -> A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) | 
						
							| 6 |  | ineq1 |  |-  ( s = B -> ( s i^i t ) = ( B i^i t ) ) | 
						
							| 7 | 6 | eqeq1d |  |-  ( s = B -> ( ( s i^i t ) = (/) <-> ( B i^i t ) = (/) ) ) | 
						
							| 8 |  | fveq2 |  |-  ( s = B -> ( I ` s ) = ( I ` B ) ) | 
						
							| 9 | 8 | ineq1d |  |-  ( s = B -> ( ( I ` s ) i^i ( I ` t ) ) = ( ( I ` B ) i^i ( I ` t ) ) ) | 
						
							| 10 | 9 | eqeq1d |  |-  ( s = B -> ( ( ( I ` s ) i^i ( I ` t ) ) = (/) <-> ( ( I ` B ) i^i ( I ` t ) ) = (/) ) ) | 
						
							| 11 | 7 10 | imbi12d |  |-  ( s = B -> ( ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) <-> ( ( B i^i t ) = (/) -> ( ( I ` B ) i^i ( I ` t ) ) = (/) ) ) ) | 
						
							| 12 |  | ineq2 |  |-  ( t = (/) -> ( B i^i t ) = ( B i^i (/) ) ) | 
						
							| 13 | 12 | eqeq1d |  |-  ( t = (/) -> ( ( B i^i t ) = (/) <-> ( B i^i (/) ) = (/) ) ) | 
						
							| 14 |  | fveq2 |  |-  ( t = (/) -> ( I ` t ) = ( I ` (/) ) ) | 
						
							| 15 | 14 | ineq2d |  |-  ( t = (/) -> ( ( I ` B ) i^i ( I ` t ) ) = ( ( I ` B ) i^i ( I ` (/) ) ) ) | 
						
							| 16 | 15 | eqeq1d |  |-  ( t = (/) -> ( ( ( I ` B ) i^i ( I ` t ) ) = (/) <-> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) ) | 
						
							| 17 | 13 16 | imbi12d |  |-  ( t = (/) -> ( ( ( B i^i t ) = (/) -> ( ( I ` B ) i^i ( I ` t ) ) = (/) ) <-> ( ( B i^i (/) ) = (/) -> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) ) ) | 
						
							| 18 |  | in0 |  |-  ( B i^i (/) ) = (/) | 
						
							| 19 |  | pm5.5 |  |-  ( ( B i^i (/) ) = (/) -> ( ( ( B i^i (/) ) = (/) -> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) <-> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) ) | 
						
							| 20 | 18 19 | mp1i |  |-  ( t = (/) -> ( ( ( B i^i (/) ) = (/) -> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) <-> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) ) | 
						
							| 21 | 17 20 | bitrd |  |-  ( t = (/) -> ( ( ( B i^i t ) = (/) -> ( ( I ` B ) i^i ( I ` t ) ) = (/) ) <-> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) ) | 
						
							| 22 | 11 21 | rspc2va |  |-  ( ( ( B e. ~P B /\ (/) e. ~P B ) /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) -> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) | 
						
							| 23 | 2 4 5 22 | syl21anc |  |-  ( ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) /\ ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) ) -> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) | 
						
							| 24 | 23 | ex |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> ( ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) -> ( ( I ` B ) i^i ( I ` (/) ) ) = (/) ) ) | 
						
							| 25 |  | elmapi |  |-  ( I e. ( ~P B ^m ~P B ) -> I : ~P B --> ~P B ) | 
						
							| 26 | 25 | adantl |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> I : ~P B --> ~P B ) | 
						
							| 27 | 3 | a1i |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> (/) e. ~P B ) | 
						
							| 28 | 26 27 | ffvelcdmd |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> ( I ` (/) ) e. ~P B ) | 
						
							| 29 | 28 | elpwid |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> ( I ` (/) ) C_ B ) | 
						
							| 30 |  | simpl |  |-  ( ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) -> ( I ` B ) = B ) | 
						
							| 31 |  | ineq1 |  |-  ( ( I ` B ) = B -> ( ( I ` B ) i^i ( I ` (/) ) ) = ( B i^i ( I ` (/) ) ) ) | 
						
							| 32 |  | incom |  |-  ( B i^i ( I ` (/) ) ) = ( ( I ` (/) ) i^i B ) | 
						
							| 33 | 31 32 | eqtrdi |  |-  ( ( I ` B ) = B -> ( ( I ` B ) i^i ( I ` (/) ) ) = ( ( I ` (/) ) i^i B ) ) | 
						
							| 34 | 33 | eqeq1d |  |-  ( ( I ` B ) = B -> ( ( ( I ` B ) i^i ( I ` (/) ) ) = (/) <-> ( ( I ` (/) ) i^i B ) = (/) ) ) | 
						
							| 35 | 34 | biimpd |  |-  ( ( I ` B ) = B -> ( ( ( I ` B ) i^i ( I ` (/) ) ) = (/) -> ( ( I ` (/) ) i^i B ) = (/) ) ) | 
						
							| 36 |  | reldisj |  |-  ( ( I ` (/) ) C_ B -> ( ( ( I ` (/) ) i^i B ) = (/) <-> ( I ` (/) ) C_ ( B \ B ) ) ) | 
						
							| 37 | 36 | biimpd |  |-  ( ( I ` (/) ) C_ B -> ( ( ( I ` (/) ) i^i B ) = (/) -> ( I ` (/) ) C_ ( B \ B ) ) ) | 
						
							| 38 |  | difid |  |-  ( B \ B ) = (/) | 
						
							| 39 | 38 | sseq2i |  |-  ( ( I ` (/) ) C_ ( B \ B ) <-> ( I ` (/) ) C_ (/) ) | 
						
							| 40 |  | ss0 |  |-  ( ( I ` (/) ) C_ (/) -> ( I ` (/) ) = (/) ) | 
						
							| 41 | 39 40 | sylbi |  |-  ( ( I ` (/) ) C_ ( B \ B ) -> ( I ` (/) ) = (/) ) | 
						
							| 42 | 37 41 | syl6com |  |-  ( ( ( I ` (/) ) i^i B ) = (/) -> ( ( I ` (/) ) C_ B -> ( I ` (/) ) = (/) ) ) | 
						
							| 43 | 35 42 | syl6com |  |-  ( ( ( I ` B ) i^i ( I ` (/) ) ) = (/) -> ( ( I ` B ) = B -> ( ( I ` (/) ) C_ B -> ( I ` (/) ) = (/) ) ) ) | 
						
							| 44 | 43 | com13 |  |-  ( ( I ` (/) ) C_ B -> ( ( I ` B ) = B -> ( ( ( I ` B ) i^i ( I ` (/) ) ) = (/) -> ( I ` (/) ) = (/) ) ) ) | 
						
							| 45 | 29 30 44 | syl2im |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> ( ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) -> ( ( ( I ` B ) i^i ( I ` (/) ) ) = (/) -> ( I ` (/) ) = (/) ) ) ) | 
						
							| 46 | 24 45 | mpdd |  |-  ( ( B e. V /\ I e. ( ~P B ^m ~P B ) ) -> ( ( ( I ` B ) = B /\ A. s e. ~P B A. t e. ~P B ( ( s i^i t ) = (/) -> ( ( I ` s ) i^i ( I ` t ) ) = (/) ) ) -> ( I ` (/) ) = (/) ) ) |