| Step | Hyp | Ref | Expression | 
						
							| 1 |  | bj-imdiridlem.1 |  |-  ( ( x C_ A /\ y C_ A ) -> ( ph <-> x = y ) ) | 
						
							| 2 | 1 | biimp3a |  |-  ( ( x C_ A /\ y C_ A /\ ph ) -> x = y ) | 
						
							| 3 | 2 | 3expib |  |-  ( x C_ A -> ( ( y C_ A /\ ph ) -> x = y ) ) | 
						
							| 4 |  | equcomi |  |-  ( x = y -> y = x ) | 
						
							| 5 | 4 | sseq1d |  |-  ( x = y -> ( y C_ A <-> x C_ A ) ) | 
						
							| 6 | 5 | biimparc |  |-  ( ( x C_ A /\ x = y ) -> y C_ A ) | 
						
							| 7 |  | simpr |  |-  ( ( ( x C_ A /\ x = y ) /\ y C_ A ) -> y C_ A ) | 
						
							| 8 | 1 | biimpar |  |-  ( ( ( x C_ A /\ y C_ A ) /\ x = y ) -> ph ) | 
						
							| 9 | 8 | an32s |  |-  ( ( ( x C_ A /\ x = y ) /\ y C_ A ) -> ph ) | 
						
							| 10 | 7 9 | jca |  |-  ( ( ( x C_ A /\ x = y ) /\ y C_ A ) -> ( y C_ A /\ ph ) ) | 
						
							| 11 | 6 10 | mpdan |  |-  ( ( x C_ A /\ x = y ) -> ( y C_ A /\ ph ) ) | 
						
							| 12 | 11 | ex |  |-  ( x C_ A -> ( x = y -> ( y C_ A /\ ph ) ) ) | 
						
							| 13 | 3 12 | impbid |  |-  ( x C_ A -> ( ( y C_ A /\ ph ) <-> x = y ) ) | 
						
							| 14 | 13 | pm5.32i |  |-  ( ( x C_ A /\ ( y C_ A /\ ph ) ) <-> ( x C_ A /\ x = y ) ) | 
						
							| 15 |  | anass |  |-  ( ( ( x C_ A /\ y C_ A ) /\ ph ) <-> ( x C_ A /\ ( y C_ A /\ ph ) ) ) | 
						
							| 16 |  | velpw |  |-  ( x e. ~P A <-> x C_ A ) | 
						
							| 17 |  | vex |  |-  y e. _V | 
						
							| 18 | 17 | ideq |  |-  ( x _I y <-> x = y ) | 
						
							| 19 | 16 18 | anbi12i |  |-  ( ( x e. ~P A /\ x _I y ) <-> ( x C_ A /\ x = y ) ) | 
						
							| 20 | 14 15 19 | 3bitr4i |  |-  ( ( ( x C_ A /\ y C_ A ) /\ ph ) <-> ( x e. ~P A /\ x _I y ) ) | 
						
							| 21 | 20 | opabbii |  |-  { <. x , y >. | ( ( x C_ A /\ y C_ A ) /\ ph ) } = { <. x , y >. | ( x e. ~P A /\ x _I y ) } | 
						
							| 22 |  | dfres2 |  |-  ( _I |` ~P A ) = { <. x , y >. | ( x e. ~P A /\ x _I y ) } | 
						
							| 23 | 21 22 | eqtr4i |  |-  { <. x , y >. | ( ( x C_ A /\ y C_ A ) /\ ph ) } = ( _I |` ~P A ) |