| Step | Hyp | Ref | Expression | 
						
							| 1 |  | erdsze2.r |  |-  ( ph -> R e. NN ) | 
						
							| 2 |  | erdsze2.s |  |-  ( ph -> S e. NN ) | 
						
							| 3 |  | erdsze2.f |  |-  ( ph -> F : A -1-1-> RR ) | 
						
							| 4 |  | erdsze2.a |  |-  ( ph -> A C_ RR ) | 
						
							| 5 |  | erdsze2lem.n |  |-  N = ( ( R - 1 ) x. ( S - 1 ) ) | 
						
							| 6 |  | erdsze2lem.l |  |-  ( ph -> N < ( # ` A ) ) | 
						
							| 7 |  | nnm1nn0 |  |-  ( R e. NN -> ( R - 1 ) e. NN0 ) | 
						
							| 8 | 1 7 | syl |  |-  ( ph -> ( R - 1 ) e. NN0 ) | 
						
							| 9 |  | nnm1nn0 |  |-  ( S e. NN -> ( S - 1 ) e. NN0 ) | 
						
							| 10 | 2 9 | syl |  |-  ( ph -> ( S - 1 ) e. NN0 ) | 
						
							| 11 | 8 10 | nn0mulcld |  |-  ( ph -> ( ( R - 1 ) x. ( S - 1 ) ) e. NN0 ) | 
						
							| 12 | 5 11 | eqeltrid |  |-  ( ph -> N e. NN0 ) | 
						
							| 13 |  | peano2nn0 |  |-  ( N e. NN0 -> ( N + 1 ) e. NN0 ) | 
						
							| 14 |  | hashfz1 |  |-  ( ( N + 1 ) e. NN0 -> ( # ` ( 1 ... ( N + 1 ) ) ) = ( N + 1 ) ) | 
						
							| 15 | 12 13 14 | 3syl |  |-  ( ph -> ( # ` ( 1 ... ( N + 1 ) ) ) = ( N + 1 ) ) | 
						
							| 16 | 15 | adantr |  |-  ( ( ph /\ A e. Fin ) -> ( # ` ( 1 ... ( N + 1 ) ) ) = ( N + 1 ) ) | 
						
							| 17 | 6 | adantr |  |-  ( ( ph /\ A e. Fin ) -> N < ( # ` A ) ) | 
						
							| 18 |  | hashcl |  |-  ( A e. Fin -> ( # ` A ) e. NN0 ) | 
						
							| 19 |  | nn0ltp1le |  |-  ( ( N e. NN0 /\ ( # ` A ) e. NN0 ) -> ( N < ( # ` A ) <-> ( N + 1 ) <_ ( # ` A ) ) ) | 
						
							| 20 | 12 18 19 | syl2an |  |-  ( ( ph /\ A e. Fin ) -> ( N < ( # ` A ) <-> ( N + 1 ) <_ ( # ` A ) ) ) | 
						
							| 21 | 17 20 | mpbid |  |-  ( ( ph /\ A e. Fin ) -> ( N + 1 ) <_ ( # ` A ) ) | 
						
							| 22 | 16 21 | eqbrtrd |  |-  ( ( ph /\ A e. Fin ) -> ( # ` ( 1 ... ( N + 1 ) ) ) <_ ( # ` A ) ) | 
						
							| 23 |  | fzfid |  |-  ( ( ph /\ A e. Fin ) -> ( 1 ... ( N + 1 ) ) e. Fin ) | 
						
							| 24 |  | simpr |  |-  ( ( ph /\ A e. Fin ) -> A e. Fin ) | 
						
							| 25 |  | hashdom |  |-  ( ( ( 1 ... ( N + 1 ) ) e. Fin /\ A e. Fin ) -> ( ( # ` ( 1 ... ( N + 1 ) ) ) <_ ( # ` A ) <-> ( 1 ... ( N + 1 ) ) ~<_ A ) ) | 
						
							| 26 | 23 24 25 | syl2anc |  |-  ( ( ph /\ A e. Fin ) -> ( ( # ` ( 1 ... ( N + 1 ) ) ) <_ ( # ` A ) <-> ( 1 ... ( N + 1 ) ) ~<_ A ) ) | 
						
							| 27 | 22 26 | mpbid |  |-  ( ( ph /\ A e. Fin ) -> ( 1 ... ( N + 1 ) ) ~<_ A ) | 
						
							| 28 |  | simpr |  |-  ( ( ph /\ -. A e. Fin ) -> -. A e. Fin ) | 
						
							| 29 |  | fzfid |  |-  ( ( ph /\ -. A e. Fin ) -> ( 1 ... ( N + 1 ) ) e. Fin ) | 
						
							| 30 |  | isinffi |  |-  ( ( -. A e. Fin /\ ( 1 ... ( N + 1 ) ) e. Fin ) -> E. f f : ( 1 ... ( N + 1 ) ) -1-1-> A ) | 
						
							| 31 | 28 29 30 | syl2anc |  |-  ( ( ph /\ -. A e. Fin ) -> E. f f : ( 1 ... ( N + 1 ) ) -1-1-> A ) | 
						
							| 32 |  | reex |  |-  RR e. _V | 
						
							| 33 |  | ssexg |  |-  ( ( A C_ RR /\ RR e. _V ) -> A e. _V ) | 
						
							| 34 | 4 32 33 | sylancl |  |-  ( ph -> A e. _V ) | 
						
							| 35 | 34 | adantr |  |-  ( ( ph /\ -. A e. Fin ) -> A e. _V ) | 
						
							| 36 |  | brdomg |  |-  ( A e. _V -> ( ( 1 ... ( N + 1 ) ) ~<_ A <-> E. f f : ( 1 ... ( N + 1 ) ) -1-1-> A ) ) | 
						
							| 37 | 35 36 | syl |  |-  ( ( ph /\ -. A e. Fin ) -> ( ( 1 ... ( N + 1 ) ) ~<_ A <-> E. f f : ( 1 ... ( N + 1 ) ) -1-1-> A ) ) | 
						
							| 38 | 31 37 | mpbird |  |-  ( ( ph /\ -. A e. Fin ) -> ( 1 ... ( N + 1 ) ) ~<_ A ) | 
						
							| 39 | 27 38 | pm2.61dan |  |-  ( ph -> ( 1 ... ( N + 1 ) ) ~<_ A ) | 
						
							| 40 |  | domeng |  |-  ( A e. _V -> ( ( 1 ... ( N + 1 ) ) ~<_ A <-> E. s ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) ) | 
						
							| 41 | 34 40 | syl |  |-  ( ph -> ( ( 1 ... ( N + 1 ) ) ~<_ A <-> E. s ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) ) | 
						
							| 42 | 39 41 | mpbid |  |-  ( ph -> E. s ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) | 
						
							| 43 |  | simprr |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> s C_ A ) | 
						
							| 44 | 4 | adantr |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> A C_ RR ) | 
						
							| 45 | 43 44 | sstrd |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> s C_ RR ) | 
						
							| 46 |  | ltso |  |-  < Or RR | 
						
							| 47 |  | soss |  |-  ( s C_ RR -> ( < Or RR -> < Or s ) ) | 
						
							| 48 | 45 46 47 | mpisyl |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> < Or s ) | 
						
							| 49 |  | fzfid |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( 1 ... ( N + 1 ) ) e. Fin ) | 
						
							| 50 |  | simprl |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( 1 ... ( N + 1 ) ) ~~ s ) | 
						
							| 51 |  | enfi |  |-  ( ( 1 ... ( N + 1 ) ) ~~ s -> ( ( 1 ... ( N + 1 ) ) e. Fin <-> s e. Fin ) ) | 
						
							| 52 | 50 51 | syl |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( ( 1 ... ( N + 1 ) ) e. Fin <-> s e. Fin ) ) | 
						
							| 53 | 49 52 | mpbid |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> s e. Fin ) | 
						
							| 54 |  | fz1iso |  |-  ( ( < Or s /\ s e. Fin ) -> E. f f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) | 
						
							| 55 | 48 53 54 | syl2anc |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> E. f f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) | 
						
							| 56 |  | isof1o |  |-  ( f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) -> f : ( 1 ... ( # ` s ) ) -1-1-onto-> s ) | 
						
							| 57 | 56 | adantl |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f : ( 1 ... ( # ` s ) ) -1-1-onto-> s ) | 
						
							| 58 |  | hashen |  |-  ( ( ( 1 ... ( N + 1 ) ) e. Fin /\ s e. Fin ) -> ( ( # ` ( 1 ... ( N + 1 ) ) ) = ( # ` s ) <-> ( 1 ... ( N + 1 ) ) ~~ s ) ) | 
						
							| 59 | 49 53 58 | syl2anc |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( ( # ` ( 1 ... ( N + 1 ) ) ) = ( # ` s ) <-> ( 1 ... ( N + 1 ) ) ~~ s ) ) | 
						
							| 60 | 50 59 | mpbird |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( # ` ( 1 ... ( N + 1 ) ) ) = ( # ` s ) ) | 
						
							| 61 | 15 | adantr |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( # ` ( 1 ... ( N + 1 ) ) ) = ( N + 1 ) ) | 
						
							| 62 | 60 61 | eqtr3d |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( # ` s ) = ( N + 1 ) ) | 
						
							| 63 | 62 | adantr |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> ( # ` s ) = ( N + 1 ) ) | 
						
							| 64 | 63 | oveq2d |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> ( 1 ... ( # ` s ) ) = ( 1 ... ( N + 1 ) ) ) | 
						
							| 65 | 64 | f1oeq2d |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> ( f : ( 1 ... ( # ` s ) ) -1-1-onto-> s <-> f : ( 1 ... ( N + 1 ) ) -1-1-onto-> s ) ) | 
						
							| 66 | 57 65 | mpbid |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f : ( 1 ... ( N + 1 ) ) -1-1-onto-> s ) | 
						
							| 67 |  | f1of1 |  |-  ( f : ( 1 ... ( N + 1 ) ) -1-1-onto-> s -> f : ( 1 ... ( N + 1 ) ) -1-1-> s ) | 
						
							| 68 | 66 67 | syl |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f : ( 1 ... ( N + 1 ) ) -1-1-> s ) | 
						
							| 69 |  | simplrr |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> s C_ A ) | 
						
							| 70 |  | f1ss |  |-  ( ( f : ( 1 ... ( N + 1 ) ) -1-1-> s /\ s C_ A ) -> f : ( 1 ... ( N + 1 ) ) -1-1-> A ) | 
						
							| 71 | 68 69 70 | syl2anc |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f : ( 1 ... ( N + 1 ) ) -1-1-> A ) | 
						
							| 72 |  | simpr |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) | 
						
							| 73 |  | f1ofo |  |-  ( f : ( 1 ... ( # ` s ) ) -1-1-onto-> s -> f : ( 1 ... ( # ` s ) ) -onto-> s ) | 
						
							| 74 |  | forn |  |-  ( f : ( 1 ... ( # ` s ) ) -onto-> s -> ran f = s ) | 
						
							| 75 |  | isoeq5 |  |-  ( ran f = s -> ( f Isom < , < ( ( 1 ... ( # ` s ) ) , ran f ) <-> f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) ) | 
						
							| 76 | 57 73 74 75 | 4syl |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> ( f Isom < , < ( ( 1 ... ( # ` s ) ) , ran f ) <-> f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) ) | 
						
							| 77 | 72 76 | mpbird |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f Isom < , < ( ( 1 ... ( # ` s ) ) , ran f ) ) | 
						
							| 78 |  | isoeq4 |  |-  ( ( 1 ... ( # ` s ) ) = ( 1 ... ( N + 1 ) ) -> ( f Isom < , < ( ( 1 ... ( # ` s ) ) , ran f ) <-> f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) | 
						
							| 79 | 64 78 | syl |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> ( f Isom < , < ( ( 1 ... ( # ` s ) ) , ran f ) <-> f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) | 
						
							| 80 | 77 79 | mpbid |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) | 
						
							| 81 | 71 80 | jca |  |-  ( ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) /\ f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) ) -> ( f : ( 1 ... ( N + 1 ) ) -1-1-> A /\ f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) | 
						
							| 82 | 81 | ex |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) -> ( f : ( 1 ... ( N + 1 ) ) -1-1-> A /\ f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) ) | 
						
							| 83 | 82 | eximdv |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> ( E. f f Isom < , < ( ( 1 ... ( # ` s ) ) , s ) -> E. f ( f : ( 1 ... ( N + 1 ) ) -1-1-> A /\ f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) ) | 
						
							| 84 | 55 83 | mpd |  |-  ( ( ph /\ ( ( 1 ... ( N + 1 ) ) ~~ s /\ s C_ A ) ) -> E. f ( f : ( 1 ... ( N + 1 ) ) -1-1-> A /\ f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) | 
						
							| 85 | 42 84 | exlimddv |  |-  ( ph -> E. f ( f : ( 1 ... ( N + 1 ) ) -1-1-> A /\ f Isom < , < ( ( 1 ... ( N + 1 ) ) , ran f ) ) ) |