| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isnacs.f |  |-  F = ( mrCls ` C ) | 
						
							| 2 |  | elfvex |  |-  ( C e. ( NoeACS ` X ) -> X e. _V ) | 
						
							| 3 |  | elfvex |  |-  ( C e. ( ACS ` X ) -> X e. _V ) | 
						
							| 4 | 3 | adantr |  |-  ( ( C e. ( ACS ` X ) /\ A. s e. C E. g e. ( ~P X i^i Fin ) s = ( F ` g ) ) -> X e. _V ) | 
						
							| 5 |  | fveq2 |  |-  ( x = X -> ( ACS ` x ) = ( ACS ` X ) ) | 
						
							| 6 |  | pweq |  |-  ( x = X -> ~P x = ~P X ) | 
						
							| 7 | 6 | ineq1d |  |-  ( x = X -> ( ~P x i^i Fin ) = ( ~P X i^i Fin ) ) | 
						
							| 8 | 7 | rexeqdv |  |-  ( x = X -> ( E. g e. ( ~P x i^i Fin ) s = ( ( mrCls ` c ) ` g ) <-> E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) ) ) | 
						
							| 9 | 8 | ralbidv |  |-  ( x = X -> ( A. s e. c E. g e. ( ~P x i^i Fin ) s = ( ( mrCls ` c ) ` g ) <-> A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) ) ) | 
						
							| 10 | 5 9 | rabeqbidv |  |-  ( x = X -> { c e. ( ACS ` x ) | A. s e. c E. g e. ( ~P x i^i Fin ) s = ( ( mrCls ` c ) ` g ) } = { c e. ( ACS ` X ) | A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) } ) | 
						
							| 11 |  | df-nacs |  |-  NoeACS = ( x e. _V |-> { c e. ( ACS ` x ) | A. s e. c E. g e. ( ~P x i^i Fin ) s = ( ( mrCls ` c ) ` g ) } ) | 
						
							| 12 |  | fvex |  |-  ( ACS ` X ) e. _V | 
						
							| 13 | 12 | rabex |  |-  { c e. ( ACS ` X ) | A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) } e. _V | 
						
							| 14 | 10 11 13 | fvmpt |  |-  ( X e. _V -> ( NoeACS ` X ) = { c e. ( ACS ` X ) | A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) } ) | 
						
							| 15 | 14 | eleq2d |  |-  ( X e. _V -> ( C e. ( NoeACS ` X ) <-> C e. { c e. ( ACS ` X ) | A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) } ) ) | 
						
							| 16 |  | fveq2 |  |-  ( c = C -> ( mrCls ` c ) = ( mrCls ` C ) ) | 
						
							| 17 | 16 1 | eqtr4di |  |-  ( c = C -> ( mrCls ` c ) = F ) | 
						
							| 18 | 17 | fveq1d |  |-  ( c = C -> ( ( mrCls ` c ) ` g ) = ( F ` g ) ) | 
						
							| 19 | 18 | eqeq2d |  |-  ( c = C -> ( s = ( ( mrCls ` c ) ` g ) <-> s = ( F ` g ) ) ) | 
						
							| 20 | 19 | rexbidv |  |-  ( c = C -> ( E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) <-> E. g e. ( ~P X i^i Fin ) s = ( F ` g ) ) ) | 
						
							| 21 | 20 | raleqbi1dv |  |-  ( c = C -> ( A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) <-> A. s e. C E. g e. ( ~P X i^i Fin ) s = ( F ` g ) ) ) | 
						
							| 22 | 21 | elrab |  |-  ( C e. { c e. ( ACS ` X ) | A. s e. c E. g e. ( ~P X i^i Fin ) s = ( ( mrCls ` c ) ` g ) } <-> ( C e. ( ACS ` X ) /\ A. s e. C E. g e. ( ~P X i^i Fin ) s = ( F ` g ) ) ) | 
						
							| 23 | 15 22 | bitrdi |  |-  ( X e. _V -> ( C e. ( NoeACS ` X ) <-> ( C e. ( ACS ` X ) /\ A. s e. C E. g e. ( ~P X i^i Fin ) s = ( F ` g ) ) ) ) | 
						
							| 24 | 2 4 23 | pm5.21nii |  |-  ( C e. ( NoeACS ` X ) <-> ( C e. ( ACS ` X ) /\ A. s e. C E. g e. ( ~P X i^i Fin ) s = ( F ` g ) ) ) |