| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fz1iso.1 |  |-  G = ( rec ( ( n e. _V |-> ( n + 1 ) ) , 1 ) |` _om ) | 
						
							| 2 |  | fz1iso.2 |  |-  B = ( NN i^i ( `' < " { ( ( # ` A ) + 1 ) } ) ) | 
						
							| 3 |  | fz1iso.3 |  |-  C = ( _om i^i ( `' G ` ( ( # ` A ) + 1 ) ) ) | 
						
							| 4 |  | fz1iso.4 |  |-  O = OrdIso ( R , A ) | 
						
							| 5 |  | hashcl |  |-  ( A e. Fin -> ( # ` A ) e. NN0 ) | 
						
							| 6 | 5 | adantl |  |-  ( ( R Or A /\ A e. Fin ) -> ( # ` A ) e. NN0 ) | 
						
							| 7 |  | nnuz |  |-  NN = ( ZZ>= ` 1 ) | 
						
							| 8 |  | 1z |  |-  1 e. ZZ | 
						
							| 9 | 8 1 | om2uzisoi |  |-  G Isom _E , < ( _om , ( ZZ>= ` 1 ) ) | 
						
							| 10 |  | isoeq5 |  |-  ( NN = ( ZZ>= ` 1 ) -> ( G Isom _E , < ( _om , NN ) <-> G Isom _E , < ( _om , ( ZZ>= ` 1 ) ) ) ) | 
						
							| 11 | 9 10 | mpbiri |  |-  ( NN = ( ZZ>= ` 1 ) -> G Isom _E , < ( _om , NN ) ) | 
						
							| 12 | 7 11 | ax-mp |  |-  G Isom _E , < ( _om , NN ) | 
						
							| 13 |  | isocnv |  |-  ( G Isom _E , < ( _om , NN ) -> `' G Isom < , _E ( NN , _om ) ) | 
						
							| 14 | 12 13 | ax-mp |  |-  `' G Isom < , _E ( NN , _om ) | 
						
							| 15 |  | nn0p1nn |  |-  ( ( # ` A ) e. NN0 -> ( ( # ` A ) + 1 ) e. NN ) | 
						
							| 16 |  | fvex |  |-  ( `' G ` ( ( # ` A ) + 1 ) ) e. _V | 
						
							| 17 | 16 | epini |  |-  ( `' _E " { ( `' G ` ( ( # ` A ) + 1 ) ) } ) = ( `' G ` ( ( # ` A ) + 1 ) ) | 
						
							| 18 | 17 | ineq2i |  |-  ( _om i^i ( `' _E " { ( `' G ` ( ( # ` A ) + 1 ) ) } ) ) = ( _om i^i ( `' G ` ( ( # ` A ) + 1 ) ) ) | 
						
							| 19 | 3 18 | eqtr4i |  |-  C = ( _om i^i ( `' _E " { ( `' G ` ( ( # ` A ) + 1 ) ) } ) ) | 
						
							| 20 | 2 19 | isoini2 |  |-  ( ( `' G Isom < , _E ( NN , _om ) /\ ( ( # ` A ) + 1 ) e. NN ) -> ( `' G |` B ) Isom < , _E ( B , C ) ) | 
						
							| 21 | 14 15 20 | sylancr |  |-  ( ( # ` A ) e. NN0 -> ( `' G |` B ) Isom < , _E ( B , C ) ) | 
						
							| 22 | 6 21 | syl |  |-  ( ( R Or A /\ A e. Fin ) -> ( `' G |` B ) Isom < , _E ( B , C ) ) | 
						
							| 23 |  | nnz |  |-  ( f e. NN -> f e. ZZ ) | 
						
							| 24 | 6 | nn0zd |  |-  ( ( R Or A /\ A e. Fin ) -> ( # ` A ) e. ZZ ) | 
						
							| 25 |  | eluz |  |-  ( ( f e. ZZ /\ ( # ` A ) e. ZZ ) -> ( ( # ` A ) e. ( ZZ>= ` f ) <-> f <_ ( # ` A ) ) ) | 
						
							| 26 | 23 24 25 | syl2anr |  |-  ( ( ( R Or A /\ A e. Fin ) /\ f e. NN ) -> ( ( # ` A ) e. ( ZZ>= ` f ) <-> f <_ ( # ` A ) ) ) | 
						
							| 27 |  | zleltp1 |  |-  ( ( f e. ZZ /\ ( # ` A ) e. ZZ ) -> ( f <_ ( # ` A ) <-> f < ( ( # ` A ) + 1 ) ) ) | 
						
							| 28 | 23 24 27 | syl2anr |  |-  ( ( ( R Or A /\ A e. Fin ) /\ f e. NN ) -> ( f <_ ( # ` A ) <-> f < ( ( # ` A ) + 1 ) ) ) | 
						
							| 29 |  | ovex |  |-  ( ( # ` A ) + 1 ) e. _V | 
						
							| 30 |  | vex |  |-  f e. _V | 
						
							| 31 | 30 | eliniseg |  |-  ( ( ( # ` A ) + 1 ) e. _V -> ( f e. ( `' < " { ( ( # ` A ) + 1 ) } ) <-> f < ( ( # ` A ) + 1 ) ) ) | 
						
							| 32 | 29 31 | ax-mp |  |-  ( f e. ( `' < " { ( ( # ` A ) + 1 ) } ) <-> f < ( ( # ` A ) + 1 ) ) | 
						
							| 33 | 28 32 | bitr4di |  |-  ( ( ( R Or A /\ A e. Fin ) /\ f e. NN ) -> ( f <_ ( # ` A ) <-> f e. ( `' < " { ( ( # ` A ) + 1 ) } ) ) ) | 
						
							| 34 | 26 33 | bitr2d |  |-  ( ( ( R Or A /\ A e. Fin ) /\ f e. NN ) -> ( f e. ( `' < " { ( ( # ` A ) + 1 ) } ) <-> ( # ` A ) e. ( ZZ>= ` f ) ) ) | 
						
							| 35 | 34 | pm5.32da |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( f e. NN /\ f e. ( `' < " { ( ( # ` A ) + 1 ) } ) ) <-> ( f e. NN /\ ( # ` A ) e. ( ZZ>= ` f ) ) ) ) | 
						
							| 36 | 2 | elin2 |  |-  ( f e. B <-> ( f e. NN /\ f e. ( `' < " { ( ( # ` A ) + 1 ) } ) ) ) | 
						
							| 37 |  | elfzuzb |  |-  ( f e. ( 1 ... ( # ` A ) ) <-> ( f e. ( ZZ>= ` 1 ) /\ ( # ` A ) e. ( ZZ>= ` f ) ) ) | 
						
							| 38 |  | elnnuz |  |-  ( f e. NN <-> f e. ( ZZ>= ` 1 ) ) | 
						
							| 39 | 38 | anbi1i |  |-  ( ( f e. NN /\ ( # ` A ) e. ( ZZ>= ` f ) ) <-> ( f e. ( ZZ>= ` 1 ) /\ ( # ` A ) e. ( ZZ>= ` f ) ) ) | 
						
							| 40 | 37 39 | bitr4i |  |-  ( f e. ( 1 ... ( # ` A ) ) <-> ( f e. NN /\ ( # ` A ) e. ( ZZ>= ` f ) ) ) | 
						
							| 41 | 35 36 40 | 3bitr4g |  |-  ( ( R Or A /\ A e. Fin ) -> ( f e. B <-> f e. ( 1 ... ( # ` A ) ) ) ) | 
						
							| 42 | 41 | eqrdv |  |-  ( ( R Or A /\ A e. Fin ) -> B = ( 1 ... ( # ` A ) ) ) | 
						
							| 43 |  | isoeq4 |  |-  ( B = ( 1 ... ( # ` A ) ) -> ( ( `' G |` B ) Isom < , _E ( B , C ) <-> ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , C ) ) ) | 
						
							| 44 | 42 43 | syl |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( `' G |` B ) Isom < , _E ( B , C ) <-> ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , C ) ) ) | 
						
							| 45 | 22 44 | mpbid |  |-  ( ( R Or A /\ A e. Fin ) -> ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , C ) ) | 
						
							| 46 | 4 | oion |  |-  ( A e. Fin -> dom O e. On ) | 
						
							| 47 | 46 | adantl |  |-  ( ( R Or A /\ A e. Fin ) -> dom O e. On ) | 
						
							| 48 |  | simpr |  |-  ( ( R Or A /\ A e. Fin ) -> A e. Fin ) | 
						
							| 49 |  | wofi |  |-  ( ( R Or A /\ A e. Fin ) -> R We A ) | 
						
							| 50 | 4 | oien |  |-  ( ( A e. Fin /\ R We A ) -> dom O ~~ A ) | 
						
							| 51 | 48 49 50 | syl2anc |  |-  ( ( R Or A /\ A e. Fin ) -> dom O ~~ A ) | 
						
							| 52 |  | enfii |  |-  ( ( A e. Fin /\ dom O ~~ A ) -> dom O e. Fin ) | 
						
							| 53 | 48 51 52 | syl2anc |  |-  ( ( R Or A /\ A e. Fin ) -> dom O e. Fin ) | 
						
							| 54 | 47 53 | elind |  |-  ( ( R Or A /\ A e. Fin ) -> dom O e. ( On i^i Fin ) ) | 
						
							| 55 |  | onfin2 |  |-  _om = ( On i^i Fin ) | 
						
							| 56 | 54 55 | eleqtrrdi |  |-  ( ( R Or A /\ A e. Fin ) -> dom O e. _om ) | 
						
							| 57 |  | eqid |  |-  ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) = ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) | 
						
							| 58 |  | 0z |  |-  0 e. ZZ | 
						
							| 59 | 1 57 8 58 | uzrdgxfr |  |-  ( dom O e. _om -> ( G ` dom O ) = ( ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) + ( 1 - 0 ) ) ) | 
						
							| 60 |  | 1m0e1 |  |-  ( 1 - 0 ) = 1 | 
						
							| 61 | 60 | oveq2i |  |-  ( ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) + ( 1 - 0 ) ) = ( ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) + 1 ) | 
						
							| 62 | 59 61 | eqtrdi |  |-  ( dom O e. _om -> ( G ` dom O ) = ( ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) + 1 ) ) | 
						
							| 63 | 56 62 | syl |  |-  ( ( R Or A /\ A e. Fin ) -> ( G ` dom O ) = ( ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) + 1 ) ) | 
						
							| 64 | 51 | ensymd |  |-  ( ( R Or A /\ A e. Fin ) -> A ~~ dom O ) | 
						
							| 65 |  | cardennn |  |-  ( ( A ~~ dom O /\ dom O e. _om ) -> ( card ` A ) = dom O ) | 
						
							| 66 | 64 56 65 | syl2anc |  |-  ( ( R Or A /\ A e. Fin ) -> ( card ` A ) = dom O ) | 
						
							| 67 | 66 | fveq2d |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` ( card ` A ) ) = ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) ) | 
						
							| 68 | 57 | hashgval |  |-  ( A e. Fin -> ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` ( card ` A ) ) = ( # ` A ) ) | 
						
							| 69 | 68 | adantl |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` ( card ` A ) ) = ( # ` A ) ) | 
						
							| 70 | 67 69 | eqtr3d |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) = ( # ` A ) ) | 
						
							| 71 | 70 | oveq1d |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( ( rec ( ( n e. _V |-> ( n + 1 ) ) , 0 ) |` _om ) ` dom O ) + 1 ) = ( ( # ` A ) + 1 ) ) | 
						
							| 72 | 63 71 | eqtrd |  |-  ( ( R Or A /\ A e. Fin ) -> ( G ` dom O ) = ( ( # ` A ) + 1 ) ) | 
						
							| 73 | 72 | fveq2d |  |-  ( ( R Or A /\ A e. Fin ) -> ( `' G ` ( G ` dom O ) ) = ( `' G ` ( ( # ` A ) + 1 ) ) ) | 
						
							| 74 |  | isof1o |  |-  ( G Isom _E , < ( _om , NN ) -> G : _om -1-1-onto-> NN ) | 
						
							| 75 | 12 74 | ax-mp |  |-  G : _om -1-1-onto-> NN | 
						
							| 76 |  | f1ocnvfv1 |  |-  ( ( G : _om -1-1-onto-> NN /\ dom O e. _om ) -> ( `' G ` ( G ` dom O ) ) = dom O ) | 
						
							| 77 | 75 56 76 | sylancr |  |-  ( ( R Or A /\ A e. Fin ) -> ( `' G ` ( G ` dom O ) ) = dom O ) | 
						
							| 78 | 73 77 | eqtr3d |  |-  ( ( R Or A /\ A e. Fin ) -> ( `' G ` ( ( # ` A ) + 1 ) ) = dom O ) | 
						
							| 79 | 78 | ineq2d |  |-  ( ( R Or A /\ A e. Fin ) -> ( _om i^i ( `' G ` ( ( # ` A ) + 1 ) ) ) = ( _om i^i dom O ) ) | 
						
							| 80 |  | ordom |  |-  Ord _om | 
						
							| 81 |  | ordelss |  |-  ( ( Ord _om /\ dom O e. _om ) -> dom O C_ _om ) | 
						
							| 82 | 80 56 81 | sylancr |  |-  ( ( R Or A /\ A e. Fin ) -> dom O C_ _om ) | 
						
							| 83 |  | sseqin2 |  |-  ( dom O C_ _om <-> ( _om i^i dom O ) = dom O ) | 
						
							| 84 | 82 83 | sylib |  |-  ( ( R Or A /\ A e. Fin ) -> ( _om i^i dom O ) = dom O ) | 
						
							| 85 | 79 84 | eqtrd |  |-  ( ( R Or A /\ A e. Fin ) -> ( _om i^i ( `' G ` ( ( # ` A ) + 1 ) ) ) = dom O ) | 
						
							| 86 | 3 85 | eqtrid |  |-  ( ( R Or A /\ A e. Fin ) -> C = dom O ) | 
						
							| 87 |  | isoeq5 |  |-  ( C = dom O -> ( ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , C ) <-> ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , dom O ) ) ) | 
						
							| 88 | 86 87 | syl |  |-  ( ( R Or A /\ A e. Fin ) -> ( ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , C ) <-> ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , dom O ) ) ) | 
						
							| 89 | 45 88 | mpbid |  |-  ( ( R Or A /\ A e. Fin ) -> ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , dom O ) ) | 
						
							| 90 | 4 | oiiso |  |-  ( ( A e. Fin /\ R We A ) -> O Isom _E , R ( dom O , A ) ) | 
						
							| 91 | 48 49 90 | syl2anc |  |-  ( ( R Or A /\ A e. Fin ) -> O Isom _E , R ( dom O , A ) ) | 
						
							| 92 |  | isotr |  |-  ( ( ( `' G |` B ) Isom < , _E ( ( 1 ... ( # ` A ) ) , dom O ) /\ O Isom _E , R ( dom O , A ) ) -> ( O o. ( `' G |` B ) ) Isom < , R ( ( 1 ... ( # ` A ) ) , A ) ) | 
						
							| 93 | 89 91 92 | syl2anc |  |-  ( ( R Or A /\ A e. Fin ) -> ( O o. ( `' G |` B ) ) Isom < , R ( ( 1 ... ( # ` A ) ) , A ) ) | 
						
							| 94 |  | isof1o |  |-  ( ( O o. ( `' G |` B ) ) Isom < , R ( ( 1 ... ( # ` A ) ) , A ) -> ( O o. ( `' G |` B ) ) : ( 1 ... ( # ` A ) ) -1-1-onto-> A ) | 
						
							| 95 |  | f1of |  |-  ( ( O o. ( `' G |` B ) ) : ( 1 ... ( # ` A ) ) -1-1-onto-> A -> ( O o. ( `' G |` B ) ) : ( 1 ... ( # ` A ) ) --> A ) | 
						
							| 96 | 93 94 95 | 3syl |  |-  ( ( R Or A /\ A e. Fin ) -> ( O o. ( `' G |` B ) ) : ( 1 ... ( # ` A ) ) --> A ) | 
						
							| 97 |  | fzfid |  |-  ( ( R Or A /\ A e. Fin ) -> ( 1 ... ( # ` A ) ) e. Fin ) | 
						
							| 98 | 96 97 | fexd |  |-  ( ( R Or A /\ A e. Fin ) -> ( O o. ( `' G |` B ) ) e. _V ) | 
						
							| 99 |  | isoeq1 |  |-  ( f = ( O o. ( `' G |` B ) ) -> ( f Isom < , R ( ( 1 ... ( # ` A ) ) , A ) <-> ( O o. ( `' G |` B ) ) Isom < , R ( ( 1 ... ( # ` A ) ) , A ) ) ) | 
						
							| 100 | 98 93 99 | spcedv |  |-  ( ( R Or A /\ A e. Fin ) -> E. f f Isom < , R ( ( 1 ... ( # ` A ) ) , A ) ) |