| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ackbijnn.1 |  |-  F = ( x e. ( ~P NN0 i^i Fin ) |-> sum_ y e. x ( 2 ^ y ) ) | 
						
							| 2 |  | hashgval2 |  |-  ( # |` _om ) = ( rec ( ( x e. _V |-> ( x + 1 ) ) , 0 ) |` _om ) | 
						
							| 3 | 2 | hashgf1o |  |-  ( # |` _om ) : _om -1-1-onto-> NN0 | 
						
							| 4 |  | sneq |  |-  ( w = y -> { w } = { y } ) | 
						
							| 5 |  | pweq |  |-  ( w = y -> ~P w = ~P y ) | 
						
							| 6 | 4 5 | xpeq12d |  |-  ( w = y -> ( { w } X. ~P w ) = ( { y } X. ~P y ) ) | 
						
							| 7 | 6 | cbviunv |  |-  U_ w e. z ( { w } X. ~P w ) = U_ y e. z ( { y } X. ~P y ) | 
						
							| 8 |  | iuneq1 |  |-  ( z = x -> U_ y e. z ( { y } X. ~P y ) = U_ y e. x ( { y } X. ~P y ) ) | 
						
							| 9 | 7 8 | eqtrid |  |-  ( z = x -> U_ w e. z ( { w } X. ~P w ) = U_ y e. x ( { y } X. ~P y ) ) | 
						
							| 10 | 9 | fveq2d |  |-  ( z = x -> ( card ` U_ w e. z ( { w } X. ~P w ) ) = ( card ` U_ y e. x ( { y } X. ~P y ) ) ) | 
						
							| 11 | 10 | cbvmptv |  |-  ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) = ( x e. ( ~P _om i^i Fin ) |-> ( card ` U_ y e. x ( { y } X. ~P y ) ) ) | 
						
							| 12 | 11 | ackbij1 |  |-  ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) : ( ~P _om i^i Fin ) -1-1-onto-> _om | 
						
							| 13 |  | f1ocnv |  |-  ( ( # |` _om ) : _om -1-1-onto-> NN0 -> `' ( # |` _om ) : NN0 -1-1-onto-> _om ) | 
						
							| 14 | 3 13 | ax-mp |  |-  `' ( # |` _om ) : NN0 -1-1-onto-> _om | 
						
							| 15 |  | f1opwfi |  |-  ( `' ( # |` _om ) : NN0 -1-1-onto-> _om -> ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> ( ~P _om i^i Fin ) ) | 
						
							| 16 | 14 15 | ax-mp |  |-  ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> ( ~P _om i^i Fin ) | 
						
							| 17 |  | f1oco |  |-  ( ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) : ( ~P _om i^i Fin ) -1-1-onto-> _om /\ ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> ( ~P _om i^i Fin ) ) -> ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> _om ) | 
						
							| 18 | 12 16 17 | mp2an |  |-  ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> _om | 
						
							| 19 |  | f1oco |  |-  ( ( ( # |` _om ) : _om -1-1-onto-> NN0 /\ ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> _om ) -> ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 ) | 
						
							| 20 | 3 18 19 | mp2an |  |-  ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 | 
						
							| 21 |  | inss2 |  |-  ( ~P _om i^i Fin ) C_ Fin | 
						
							| 22 |  | f1of |  |-  ( ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> ( ~P _om i^i Fin ) -> ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) --> ( ~P _om i^i Fin ) ) | 
						
							| 23 | 16 22 | ax-mp |  |-  ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) --> ( ~P _om i^i Fin ) | 
						
							| 24 |  | eqid |  |-  ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) = ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) | 
						
							| 25 | 24 | fmpt |  |-  ( A. x e. ( ~P NN0 i^i Fin ) ( `' ( # |` _om ) " x ) e. ( ~P _om i^i Fin ) <-> ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) : ( ~P NN0 i^i Fin ) --> ( ~P _om i^i Fin ) ) | 
						
							| 26 | 23 25 | mpbir |  |-  A. x e. ( ~P NN0 i^i Fin ) ( `' ( # |` _om ) " x ) e. ( ~P _om i^i Fin ) | 
						
							| 27 | 26 | rspec |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( `' ( # |` _om ) " x ) e. ( ~P _om i^i Fin ) ) | 
						
							| 28 | 21 27 | sselid |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( `' ( # |` _om ) " x ) e. Fin ) | 
						
							| 29 |  | snfi |  |-  { w } e. Fin | 
						
							| 30 |  | cnvimass |  |-  ( `' ( # |` _om ) " x ) C_ dom ( # |` _om ) | 
						
							| 31 |  | dmhashres |  |-  dom ( # |` _om ) = _om | 
						
							| 32 | 30 31 | sseqtri |  |-  ( `' ( # |` _om ) " x ) C_ _om | 
						
							| 33 |  | onfin2 |  |-  _om = ( On i^i Fin ) | 
						
							| 34 |  | inss2 |  |-  ( On i^i Fin ) C_ Fin | 
						
							| 35 | 33 34 | eqsstri |  |-  _om C_ Fin | 
						
							| 36 | 32 35 | sstri |  |-  ( `' ( # |` _om ) " x ) C_ Fin | 
						
							| 37 |  | simpr |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ w e. ( `' ( # |` _om ) " x ) ) -> w e. ( `' ( # |` _om ) " x ) ) | 
						
							| 38 | 36 37 | sselid |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ w e. ( `' ( # |` _om ) " x ) ) -> w e. Fin ) | 
						
							| 39 |  | pwfi |  |-  ( w e. Fin <-> ~P w e. Fin ) | 
						
							| 40 | 38 39 | sylib |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ w e. ( `' ( # |` _om ) " x ) ) -> ~P w e. Fin ) | 
						
							| 41 |  | xpfi |  |-  ( ( { w } e. Fin /\ ~P w e. Fin ) -> ( { w } X. ~P w ) e. Fin ) | 
						
							| 42 | 29 40 41 | sylancr |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ w e. ( `' ( # |` _om ) " x ) ) -> ( { w } X. ~P w ) e. Fin ) | 
						
							| 43 | 42 | ralrimiva |  |-  ( x e. ( ~P NN0 i^i Fin ) -> A. w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) e. Fin ) | 
						
							| 44 |  | iunfi |  |-  ( ( ( `' ( # |` _om ) " x ) e. Fin /\ A. w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) e. Fin ) -> U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) e. Fin ) | 
						
							| 45 | 28 43 44 | syl2anc |  |-  ( x e. ( ~P NN0 i^i Fin ) -> U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) e. Fin ) | 
						
							| 46 |  | ficardom |  |-  ( U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) e. Fin -> ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) e. _om ) | 
						
							| 47 | 45 46 | syl |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) e. _om ) | 
						
							| 48 | 47 | fvresd |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( ( # |` _om ) ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) = ( # ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) ) | 
						
							| 49 |  | hashcard |  |-  ( U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) e. Fin -> ( # ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) = ( # ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) | 
						
							| 50 | 45 49 | syl |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( # ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) = ( # ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) | 
						
							| 51 |  | xp1st |  |-  ( z e. ( { w } X. ~P w ) -> ( 1st ` z ) e. { w } ) | 
						
							| 52 |  | elsni |  |-  ( ( 1st ` z ) e. { w } -> ( 1st ` z ) = w ) | 
						
							| 53 | 51 52 | syl |  |-  ( z e. ( { w } X. ~P w ) -> ( 1st ` z ) = w ) | 
						
							| 54 | 53 | rgen |  |-  A. z e. ( { w } X. ~P w ) ( 1st ` z ) = w | 
						
							| 55 | 54 | rgenw |  |-  A. w e. ( `' ( # |` _om ) " x ) A. z e. ( { w } X. ~P w ) ( 1st ` z ) = w | 
						
							| 56 |  | invdisj |  |-  ( A. w e. ( `' ( # |` _om ) " x ) A. z e. ( { w } X. ~P w ) ( 1st ` z ) = w -> Disj_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) | 
						
							| 57 | 55 56 | mp1i |  |-  ( x e. ( ~P NN0 i^i Fin ) -> Disj_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) | 
						
							| 58 | 28 42 57 | hashiun |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( # ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) = sum_ w e. ( `' ( # |` _om ) " x ) ( # ` ( { w } X. ~P w ) ) ) | 
						
							| 59 |  | sneq |  |-  ( w = ( `' ( # |` _om ) ` y ) -> { w } = { ( `' ( # |` _om ) ` y ) } ) | 
						
							| 60 |  | pweq |  |-  ( w = ( `' ( # |` _om ) ` y ) -> ~P w = ~P ( `' ( # |` _om ) ` y ) ) | 
						
							| 61 | 59 60 | xpeq12d |  |-  ( w = ( `' ( # |` _om ) ` y ) -> ( { w } X. ~P w ) = ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) | 
						
							| 62 | 61 | fveq2d |  |-  ( w = ( `' ( # |` _om ) ` y ) -> ( # ` ( { w } X. ~P w ) ) = ( # ` ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) ) | 
						
							| 63 |  | elinel2 |  |-  ( x e. ( ~P NN0 i^i Fin ) -> x e. Fin ) | 
						
							| 64 |  | f1of1 |  |-  ( `' ( # |` _om ) : NN0 -1-1-onto-> _om -> `' ( # |` _om ) : NN0 -1-1-> _om ) | 
						
							| 65 | 14 64 | ax-mp |  |-  `' ( # |` _om ) : NN0 -1-1-> _om | 
						
							| 66 |  | elinel1 |  |-  ( x e. ( ~P NN0 i^i Fin ) -> x e. ~P NN0 ) | 
						
							| 67 | 66 | elpwid |  |-  ( x e. ( ~P NN0 i^i Fin ) -> x C_ NN0 ) | 
						
							| 68 |  | f1ores |  |-  ( ( `' ( # |` _om ) : NN0 -1-1-> _om /\ x C_ NN0 ) -> ( `' ( # |` _om ) |` x ) : x -1-1-onto-> ( `' ( # |` _om ) " x ) ) | 
						
							| 69 | 65 67 68 | sylancr |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( `' ( # |` _om ) |` x ) : x -1-1-onto-> ( `' ( # |` _om ) " x ) ) | 
						
							| 70 |  | fvres |  |-  ( y e. x -> ( ( `' ( # |` _om ) |` x ) ` y ) = ( `' ( # |` _om ) ` y ) ) | 
						
							| 71 | 70 | adantl |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( ( `' ( # |` _om ) |` x ) ` y ) = ( `' ( # |` _om ) ` y ) ) | 
						
							| 72 |  | hashcl |  |-  ( ( { w } X. ~P w ) e. Fin -> ( # ` ( { w } X. ~P w ) ) e. NN0 ) | 
						
							| 73 |  | nn0cn |  |-  ( ( # ` ( { w } X. ~P w ) ) e. NN0 -> ( # ` ( { w } X. ~P w ) ) e. CC ) | 
						
							| 74 | 42 72 73 | 3syl |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ w e. ( `' ( # |` _om ) " x ) ) -> ( # ` ( { w } X. ~P w ) ) e. CC ) | 
						
							| 75 | 62 63 69 71 74 | fsumf1o |  |-  ( x e. ( ~P NN0 i^i Fin ) -> sum_ w e. ( `' ( # |` _om ) " x ) ( # ` ( { w } X. ~P w ) ) = sum_ y e. x ( # ` ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) ) | 
						
							| 76 |  | snfi |  |-  { ( `' ( # |` _om ) ` y ) } e. Fin | 
						
							| 77 | 67 | sselda |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> y e. NN0 ) | 
						
							| 78 |  | f1of |  |-  ( `' ( # |` _om ) : NN0 -1-1-onto-> _om -> `' ( # |` _om ) : NN0 --> _om ) | 
						
							| 79 | 14 78 | ax-mp |  |-  `' ( # |` _om ) : NN0 --> _om | 
						
							| 80 | 79 | ffvelcdmi |  |-  ( y e. NN0 -> ( `' ( # |` _om ) ` y ) e. _om ) | 
						
							| 81 | 77 80 | syl |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( `' ( # |` _om ) ` y ) e. _om ) | 
						
							| 82 | 35 81 | sselid |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( `' ( # |` _om ) ` y ) e. Fin ) | 
						
							| 83 |  | pwfi |  |-  ( ( `' ( # |` _om ) ` y ) e. Fin <-> ~P ( `' ( # |` _om ) ` y ) e. Fin ) | 
						
							| 84 | 82 83 | sylib |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ~P ( `' ( # |` _om ) ` y ) e. Fin ) | 
						
							| 85 |  | hashxp |  |-  ( ( { ( `' ( # |` _om ) ` y ) } e. Fin /\ ~P ( `' ( # |` _om ) ` y ) e. Fin ) -> ( # ` ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) = ( ( # ` { ( `' ( # |` _om ) ` y ) } ) x. ( # ` ~P ( `' ( # |` _om ) ` y ) ) ) ) | 
						
							| 86 | 76 84 85 | sylancr |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( # ` ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) = ( ( # ` { ( `' ( # |` _om ) ` y ) } ) x. ( # ` ~P ( `' ( # |` _om ) ` y ) ) ) ) | 
						
							| 87 |  | hashsng |  |-  ( ( `' ( # |` _om ) ` y ) e. _om -> ( # ` { ( `' ( # |` _om ) ` y ) } ) = 1 ) | 
						
							| 88 | 81 87 | syl |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( # ` { ( `' ( # |` _om ) ` y ) } ) = 1 ) | 
						
							| 89 |  | hashpw |  |-  ( ( `' ( # |` _om ) ` y ) e. Fin -> ( # ` ~P ( `' ( # |` _om ) ` y ) ) = ( 2 ^ ( # ` ( `' ( # |` _om ) ` y ) ) ) ) | 
						
							| 90 | 82 89 | syl |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( # ` ~P ( `' ( # |` _om ) ` y ) ) = ( 2 ^ ( # ` ( `' ( # |` _om ) ` y ) ) ) ) | 
						
							| 91 | 81 | fvresd |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( ( # |` _om ) ` ( `' ( # |` _om ) ` y ) ) = ( # ` ( `' ( # |` _om ) ` y ) ) ) | 
						
							| 92 |  | f1ocnvfv2 |  |-  ( ( ( # |` _om ) : _om -1-1-onto-> NN0 /\ y e. NN0 ) -> ( ( # |` _om ) ` ( `' ( # |` _om ) ` y ) ) = y ) | 
						
							| 93 | 3 77 92 | sylancr |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( ( # |` _om ) ` ( `' ( # |` _om ) ` y ) ) = y ) | 
						
							| 94 | 91 93 | eqtr3d |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( # ` ( `' ( # |` _om ) ` y ) ) = y ) | 
						
							| 95 | 94 | oveq2d |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( 2 ^ ( # ` ( `' ( # |` _om ) ` y ) ) ) = ( 2 ^ y ) ) | 
						
							| 96 | 90 95 | eqtrd |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( # ` ~P ( `' ( # |` _om ) ` y ) ) = ( 2 ^ y ) ) | 
						
							| 97 | 88 96 | oveq12d |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( ( # ` { ( `' ( # |` _om ) ` y ) } ) x. ( # ` ~P ( `' ( # |` _om ) ` y ) ) ) = ( 1 x. ( 2 ^ y ) ) ) | 
						
							| 98 |  | 2cn |  |-  2 e. CC | 
						
							| 99 |  | expcl |  |-  ( ( 2 e. CC /\ y e. NN0 ) -> ( 2 ^ y ) e. CC ) | 
						
							| 100 | 98 77 99 | sylancr |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( 2 ^ y ) e. CC ) | 
						
							| 101 | 100 | mullidd |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( 1 x. ( 2 ^ y ) ) = ( 2 ^ y ) ) | 
						
							| 102 | 86 97 101 | 3eqtrd |  |-  ( ( x e. ( ~P NN0 i^i Fin ) /\ y e. x ) -> ( # ` ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) = ( 2 ^ y ) ) | 
						
							| 103 | 102 | sumeq2dv |  |-  ( x e. ( ~P NN0 i^i Fin ) -> sum_ y e. x ( # ` ( { ( `' ( # |` _om ) ` y ) } X. ~P ( `' ( # |` _om ) ` y ) ) ) = sum_ y e. x ( 2 ^ y ) ) | 
						
							| 104 | 58 75 103 | 3eqtrd |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( # ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) = sum_ y e. x ( 2 ^ y ) ) | 
						
							| 105 | 48 50 104 | 3eqtrd |  |-  ( x e. ( ~P NN0 i^i Fin ) -> ( ( # |` _om ) ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) = sum_ y e. x ( 2 ^ y ) ) | 
						
							| 106 | 105 | mpteq2ia |  |-  ( x e. ( ~P NN0 i^i Fin ) |-> ( ( # |` _om ) ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) ) = ( x e. ( ~P NN0 i^i Fin ) |-> sum_ y e. x ( 2 ^ y ) ) | 
						
							| 107 | 47 | adantl |  |-  ( ( T. /\ x e. ( ~P NN0 i^i Fin ) ) -> ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) e. _om ) | 
						
							| 108 | 27 | adantl |  |-  ( ( T. /\ x e. ( ~P NN0 i^i Fin ) ) -> ( `' ( # |` _om ) " x ) e. ( ~P _om i^i Fin ) ) | 
						
							| 109 |  | eqidd |  |-  ( T. -> ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) = ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) | 
						
							| 110 |  | eqidd |  |-  ( T. -> ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) = ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) ) | 
						
							| 111 |  | iuneq1 |  |-  ( z = ( `' ( # |` _om ) " x ) -> U_ w e. z ( { w } X. ~P w ) = U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) | 
						
							| 112 | 111 | fveq2d |  |-  ( z = ( `' ( # |` _om ) " x ) -> ( card ` U_ w e. z ( { w } X. ~P w ) ) = ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) | 
						
							| 113 | 108 109 110 112 | fmptco |  |-  ( T. -> ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) = ( x e. ( ~P NN0 i^i Fin ) |-> ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) ) | 
						
							| 114 |  | f1of |  |-  ( ( # |` _om ) : _om -1-1-onto-> NN0 -> ( # |` _om ) : _om --> NN0 ) | 
						
							| 115 | 3 114 | mp1i |  |-  ( T. -> ( # |` _om ) : _om --> NN0 ) | 
						
							| 116 | 115 | feqmptd |  |-  ( T. -> ( # |` _om ) = ( y e. _om |-> ( ( # |` _om ) ` y ) ) ) | 
						
							| 117 |  | fveq2 |  |-  ( y = ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) -> ( ( # |` _om ) ` y ) = ( ( # |` _om ) ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) ) | 
						
							| 118 | 107 113 116 117 | fmptco |  |-  ( T. -> ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) = ( x e. ( ~P NN0 i^i Fin ) |-> ( ( # |` _om ) ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) ) ) | 
						
							| 119 | 118 | mptru |  |-  ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) = ( x e. ( ~P NN0 i^i Fin ) |-> ( ( # |` _om ) ` ( card ` U_ w e. ( `' ( # |` _om ) " x ) ( { w } X. ~P w ) ) ) ) | 
						
							| 120 | 106 119 1 | 3eqtr4i |  |-  ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) = F | 
						
							| 121 |  | f1oeq1 |  |-  ( ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) = F -> ( ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 <-> F : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 ) ) | 
						
							| 122 | 120 121 | ax-mp |  |-  ( ( ( # |` _om ) o. ( ( z e. ( ~P _om i^i Fin ) |-> ( card ` U_ w e. z ( { w } X. ~P w ) ) ) o. ( x e. ( ~P NN0 i^i Fin ) |-> ( `' ( # |` _om ) " x ) ) ) ) : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 <-> F : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 ) | 
						
							| 123 | 20 122 | mpbi |  |-  F : ( ~P NN0 i^i Fin ) -1-1-onto-> NN0 |