| Step | Hyp | Ref | Expression | 
						
							| 1 |  | bj-imdirvallem.1 |  |-  ( ph -> A e. U ) | 
						
							| 2 |  | bj-imdirvallem.2 |  |-  ( ph -> B e. V ) | 
						
							| 3 |  | bj-imdirvallem.df |  |-  C = ( a e. _V , b e. _V |-> ( r e. ~P ( a X. b ) |-> { <. x , y >. | ( ( x C_ a /\ y C_ b ) /\ ps ) } ) ) | 
						
							| 4 | 3 | a1i |  |-  ( ph -> C = ( a e. _V , b e. _V |-> ( r e. ~P ( a X. b ) |-> { <. x , y >. | ( ( x C_ a /\ y C_ b ) /\ ps ) } ) ) ) | 
						
							| 5 |  | xpeq12 |  |-  ( ( a = A /\ b = B ) -> ( a X. b ) = ( A X. B ) ) | 
						
							| 6 | 5 | pweqd |  |-  ( ( a = A /\ b = B ) -> ~P ( a X. b ) = ~P ( A X. B ) ) | 
						
							| 7 | 6 | adantl |  |-  ( ( ph /\ ( a = A /\ b = B ) ) -> ~P ( a X. b ) = ~P ( A X. B ) ) | 
						
							| 8 |  | sseq2 |  |-  ( a = A -> ( x C_ a <-> x C_ A ) ) | 
						
							| 9 |  | sseq2 |  |-  ( b = B -> ( y C_ b <-> y C_ B ) ) | 
						
							| 10 | 8 9 | bi2anan9 |  |-  ( ( a = A /\ b = B ) -> ( ( x C_ a /\ y C_ b ) <-> ( x C_ A /\ y C_ B ) ) ) | 
						
							| 11 | 10 | anbi1d |  |-  ( ( a = A /\ b = B ) -> ( ( ( x C_ a /\ y C_ b ) /\ ps ) <-> ( ( x C_ A /\ y C_ B ) /\ ps ) ) ) | 
						
							| 12 | 11 | opabbidv |  |-  ( ( a = A /\ b = B ) -> { <. x , y >. | ( ( x C_ a /\ y C_ b ) /\ ps ) } = { <. x , y >. | ( ( x C_ A /\ y C_ B ) /\ ps ) } ) | 
						
							| 13 | 12 | adantl |  |-  ( ( ph /\ ( a = A /\ b = B ) ) -> { <. x , y >. | ( ( x C_ a /\ y C_ b ) /\ ps ) } = { <. x , y >. | ( ( x C_ A /\ y C_ B ) /\ ps ) } ) | 
						
							| 14 | 7 13 | mpteq12dv |  |-  ( ( ph /\ ( a = A /\ b = B ) ) -> ( r e. ~P ( a X. b ) |-> { <. x , y >. | ( ( x C_ a /\ y C_ b ) /\ ps ) } ) = ( r e. ~P ( A X. B ) |-> { <. x , y >. | ( ( x C_ A /\ y C_ B ) /\ ps ) } ) ) | 
						
							| 15 | 1 | elexd |  |-  ( ph -> A e. _V ) | 
						
							| 16 | 2 | elexd |  |-  ( ph -> B e. _V ) | 
						
							| 17 | 1 2 | xpexd |  |-  ( ph -> ( A X. B ) e. _V ) | 
						
							| 18 | 17 | pwexd |  |-  ( ph -> ~P ( A X. B ) e. _V ) | 
						
							| 19 | 18 | mptexd |  |-  ( ph -> ( r e. ~P ( A X. B ) |-> { <. x , y >. | ( ( x C_ A /\ y C_ B ) /\ ps ) } ) e. _V ) | 
						
							| 20 | 4 14 15 16 19 | ovmpod |  |-  ( ph -> ( A C B ) = ( r e. ~P ( A X. B ) |-> { <. x , y >. | ( ( x C_ A /\ y C_ B ) /\ ps ) } ) ) |