| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elfzelz |  |-  ( k e. ( 0 ... N ) -> k e. ZZ ) | 
						
							| 2 |  | bcpascm1 |  |-  ( ( N e. NN /\ k e. ZZ ) -> ( ( ( N - 1 ) _C k ) + ( ( N - 1 ) _C ( k - 1 ) ) ) = ( N _C k ) ) | 
						
							| 3 | 1 2 | sylan2 |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( ( N - 1 ) _C k ) + ( ( N - 1 ) _C ( k - 1 ) ) ) = ( N _C k ) ) | 
						
							| 4 | 3 | eqcomd |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( N _C k ) = ( ( ( N - 1 ) _C k ) + ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 5 | 4 | oveq2d |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( -u 1 ^ k ) x. ( N _C k ) ) = ( ( -u 1 ^ k ) x. ( ( ( N - 1 ) _C k ) + ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 6 |  | ax-1cn |  |-  1 e. CC | 
						
							| 7 |  | negcl |  |-  ( 1 e. CC -> -u 1 e. CC ) | 
						
							| 8 |  | elfznn0 |  |-  ( k e. ( 0 ... N ) -> k e. NN0 ) | 
						
							| 9 |  | expcl |  |-  ( ( -u 1 e. CC /\ k e. NN0 ) -> ( -u 1 ^ k ) e. CC ) | 
						
							| 10 | 7 8 9 | syl2an |  |-  ( ( 1 e. CC /\ k e. ( 0 ... N ) ) -> ( -u 1 ^ k ) e. CC ) | 
						
							| 11 | 6 10 | mpan |  |-  ( k e. ( 0 ... N ) -> ( -u 1 ^ k ) e. CC ) | 
						
							| 12 | 11 | adantl |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( -u 1 ^ k ) e. CC ) | 
						
							| 13 |  | nnm1nn0 |  |-  ( N e. NN -> ( N - 1 ) e. NN0 ) | 
						
							| 14 |  | bccl |  |-  ( ( ( N - 1 ) e. NN0 /\ k e. ZZ ) -> ( ( N - 1 ) _C k ) e. NN0 ) | 
						
							| 15 | 14 | nn0cnd |  |-  ( ( ( N - 1 ) e. NN0 /\ k e. ZZ ) -> ( ( N - 1 ) _C k ) e. CC ) | 
						
							| 16 | 13 1 15 | syl2an |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( N - 1 ) _C k ) e. CC ) | 
						
							| 17 |  | peano2zm |  |-  ( k e. ZZ -> ( k - 1 ) e. ZZ ) | 
						
							| 18 | 1 17 | syl |  |-  ( k e. ( 0 ... N ) -> ( k - 1 ) e. ZZ ) | 
						
							| 19 |  | bccl |  |-  ( ( ( N - 1 ) e. NN0 /\ ( k - 1 ) e. ZZ ) -> ( ( N - 1 ) _C ( k - 1 ) ) e. NN0 ) | 
						
							| 20 | 19 | nn0cnd |  |-  ( ( ( N - 1 ) e. NN0 /\ ( k - 1 ) e. ZZ ) -> ( ( N - 1 ) _C ( k - 1 ) ) e. CC ) | 
						
							| 21 | 13 18 20 | syl2an |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( N - 1 ) _C ( k - 1 ) ) e. CC ) | 
						
							| 22 | 12 16 21 | adddid |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( -u 1 ^ k ) x. ( ( ( N - 1 ) _C k ) + ( ( N - 1 ) _C ( k - 1 ) ) ) ) = ( ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 23 | 5 22 | eqtrd |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( -u 1 ^ k ) x. ( N _C k ) ) = ( ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 24 | 23 | sumeq2dv |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( N _C k ) ) = sum_ k e. ( 0 ... N ) ( ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 25 |  | fzfid |  |-  ( N e. NN -> ( 0 ... N ) e. Fin ) | 
						
							| 26 |  | neg1cn |  |-  -u 1 e. CC | 
						
							| 27 | 26 | a1i |  |-  ( N e. NN -> -u 1 e. CC ) | 
						
							| 28 | 27 8 9 | syl2an |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( -u 1 ^ k ) e. CC ) | 
						
							| 29 | 28 16 | mulcld |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) e. CC ) | 
						
							| 30 |  | 1z |  |-  1 e. ZZ | 
						
							| 31 | 30 | a1i |  |-  ( k e. ( 0 ... N ) -> 1 e. ZZ ) | 
						
							| 32 | 1 31 | zsubcld |  |-  ( k e. ( 0 ... N ) -> ( k - 1 ) e. ZZ ) | 
						
							| 33 | 13 32 20 | syl2an |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( N - 1 ) _C ( k - 1 ) ) e. CC ) | 
						
							| 34 | 28 33 | mulcld |  |-  ( ( N e. NN /\ k e. ( 0 ... N ) ) -> ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) e. CC ) | 
						
							| 35 | 25 29 34 | fsumadd |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = ( sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 36 | 30 | a1i |  |-  ( N e. NN -> 1 e. ZZ ) | 
						
							| 37 |  | 0zd |  |-  ( N e. NN -> 0 e. ZZ ) | 
						
							| 38 |  | nnz |  |-  ( N e. NN -> N e. ZZ ) | 
						
							| 39 |  | oveq2 |  |-  ( k = ( j - 1 ) -> ( -u 1 ^ k ) = ( -u 1 ^ ( j - 1 ) ) ) | 
						
							| 40 |  | oveq2 |  |-  ( k = ( j - 1 ) -> ( ( N - 1 ) _C k ) = ( ( N - 1 ) _C ( j - 1 ) ) ) | 
						
							| 41 | 39 40 | oveq12d |  |-  ( k = ( j - 1 ) -> ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) = ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) ) | 
						
							| 42 | 36 37 38 29 41 | fsumshft |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) = sum_ j e. ( ( 0 + 1 ) ... ( N + 1 ) ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) ) | 
						
							| 43 |  | 0p1e1 |  |-  ( 0 + 1 ) = 1 | 
						
							| 44 | 43 | oveq1i |  |-  ( ( 0 + 1 ) ... ( N + 1 ) ) = ( 1 ... ( N + 1 ) ) | 
						
							| 45 | 44 | a1i |  |-  ( N e. NN -> ( ( 0 + 1 ) ... ( N + 1 ) ) = ( 1 ... ( N + 1 ) ) ) | 
						
							| 46 | 45 | sumeq1d |  |-  ( N e. NN -> sum_ j e. ( ( 0 + 1 ) ... ( N + 1 ) ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = sum_ j e. ( 1 ... ( N + 1 ) ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) ) | 
						
							| 47 |  | elnnuz |  |-  ( N e. NN <-> N e. ( ZZ>= ` 1 ) ) | 
						
							| 48 | 47 | biimpi |  |-  ( N e. NN -> N e. ( ZZ>= ` 1 ) ) | 
						
							| 49 | 26 | a1i |  |-  ( ( N e. NN /\ j e. ( 1 ... ( N + 1 ) ) ) -> -u 1 e. CC ) | 
						
							| 50 |  | elfznn |  |-  ( j e. ( 1 ... ( N + 1 ) ) -> j e. NN ) | 
						
							| 51 |  | nnm1nn0 |  |-  ( j e. NN -> ( j - 1 ) e. NN0 ) | 
						
							| 52 | 50 51 | syl |  |-  ( j e. ( 1 ... ( N + 1 ) ) -> ( j - 1 ) e. NN0 ) | 
						
							| 53 | 52 | adantl |  |-  ( ( N e. NN /\ j e. ( 1 ... ( N + 1 ) ) ) -> ( j - 1 ) e. NN0 ) | 
						
							| 54 | 49 53 | expcld |  |-  ( ( N e. NN /\ j e. ( 1 ... ( N + 1 ) ) ) -> ( -u 1 ^ ( j - 1 ) ) e. CC ) | 
						
							| 55 |  | elfzelz |  |-  ( j e. ( 1 ... ( N + 1 ) ) -> j e. ZZ ) | 
						
							| 56 |  | elfzel1 |  |-  ( j e. ( 1 ... ( N + 1 ) ) -> 1 e. ZZ ) | 
						
							| 57 | 55 56 | zsubcld |  |-  ( j e. ( 1 ... ( N + 1 ) ) -> ( j - 1 ) e. ZZ ) | 
						
							| 58 |  | bccl |  |-  ( ( ( N - 1 ) e. NN0 /\ ( j - 1 ) e. ZZ ) -> ( ( N - 1 ) _C ( j - 1 ) ) e. NN0 ) | 
						
							| 59 | 58 | nn0cnd |  |-  ( ( ( N - 1 ) e. NN0 /\ ( j - 1 ) e. ZZ ) -> ( ( N - 1 ) _C ( j - 1 ) ) e. CC ) | 
						
							| 60 | 13 57 59 | syl2an |  |-  ( ( N e. NN /\ j e. ( 1 ... ( N + 1 ) ) ) -> ( ( N - 1 ) _C ( j - 1 ) ) e. CC ) | 
						
							| 61 | 54 60 | mulcld |  |-  ( ( N e. NN /\ j e. ( 1 ... ( N + 1 ) ) ) -> ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) e. CC ) | 
						
							| 62 |  | oveq1 |  |-  ( j = ( N + 1 ) -> ( j - 1 ) = ( ( N + 1 ) - 1 ) ) | 
						
							| 63 | 62 | oveq2d |  |-  ( j = ( N + 1 ) -> ( -u 1 ^ ( j - 1 ) ) = ( -u 1 ^ ( ( N + 1 ) - 1 ) ) ) | 
						
							| 64 | 62 | oveq2d |  |-  ( j = ( N + 1 ) -> ( ( N - 1 ) _C ( j - 1 ) ) = ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) ) | 
						
							| 65 | 63 64 | oveq12d |  |-  ( j = ( N + 1 ) -> ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) ) ) | 
						
							| 66 | 48 61 65 | fsump1 |  |-  ( N e. NN -> sum_ j e. ( 1 ... ( N + 1 ) ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = ( sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) + ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) ) ) ) | 
						
							| 67 |  | nncn |  |-  ( N e. NN -> N e. CC ) | 
						
							| 68 |  | pncan1 |  |-  ( N e. CC -> ( ( N + 1 ) - 1 ) = N ) | 
						
							| 69 | 67 68 | syl |  |-  ( N e. NN -> ( ( N + 1 ) - 1 ) = N ) | 
						
							| 70 |  | nnnn0 |  |-  ( N e. NN -> N e. NN0 ) | 
						
							| 71 | 69 70 | eqeltrd |  |-  ( N e. NN -> ( ( N + 1 ) - 1 ) e. NN0 ) | 
						
							| 72 | 71 | nn0zd |  |-  ( N e. NN -> ( ( N + 1 ) - 1 ) e. ZZ ) | 
						
							| 73 |  | nnre |  |-  ( N e. NN -> N e. RR ) | 
						
							| 74 |  | ltm1 |  |-  ( N e. RR -> ( N - 1 ) < N ) | 
						
							| 75 | 73 74 | syl |  |-  ( N e. NN -> ( N - 1 ) < N ) | 
						
							| 76 | 75 69 | breqtrrd |  |-  ( N e. NN -> ( N - 1 ) < ( ( N + 1 ) - 1 ) ) | 
						
							| 77 | 76 | olcd |  |-  ( N e. NN -> ( ( ( N + 1 ) - 1 ) < 0 \/ ( N - 1 ) < ( ( N + 1 ) - 1 ) ) ) | 
						
							| 78 |  | bcval4 |  |-  ( ( ( N - 1 ) e. NN0 /\ ( ( N + 1 ) - 1 ) e. ZZ /\ ( ( ( N + 1 ) - 1 ) < 0 \/ ( N - 1 ) < ( ( N + 1 ) - 1 ) ) ) -> ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) = 0 ) | 
						
							| 79 | 13 72 77 78 | syl3anc |  |-  ( N e. NN -> ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) = 0 ) | 
						
							| 80 | 79 | oveq2d |  |-  ( N e. NN -> ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) ) = ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. 0 ) ) | 
						
							| 81 | 27 71 | expcld |  |-  ( N e. NN -> ( -u 1 ^ ( ( N + 1 ) - 1 ) ) e. CC ) | 
						
							| 82 | 81 | mul01d |  |-  ( N e. NN -> ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. 0 ) = 0 ) | 
						
							| 83 | 80 82 | eqtrd |  |-  ( N e. NN -> ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) ) = 0 ) | 
						
							| 84 | 83 | oveq2d |  |-  ( N e. NN -> ( sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) + ( ( -u 1 ^ ( ( N + 1 ) - 1 ) ) x. ( ( N - 1 ) _C ( ( N + 1 ) - 1 ) ) ) ) = ( sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) + 0 ) ) | 
						
							| 85 |  | oveq1 |  |-  ( j = k -> ( j - 1 ) = ( k - 1 ) ) | 
						
							| 86 | 85 | oveq2d |  |-  ( j = k -> ( -u 1 ^ ( j - 1 ) ) = ( -u 1 ^ ( k - 1 ) ) ) | 
						
							| 87 | 85 | oveq2d |  |-  ( j = k -> ( ( N - 1 ) _C ( j - 1 ) ) = ( ( N - 1 ) _C ( k - 1 ) ) ) | 
						
							| 88 | 86 87 | oveq12d |  |-  ( j = k -> ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 89 | 88 | cbvsumv |  |-  sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) | 
						
							| 90 | 89 | a1i |  |-  ( N e. NN -> sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 91 | 90 | oveq1d |  |-  ( N e. NN -> ( sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) + 0 ) = ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + 0 ) ) | 
						
							| 92 |  | fzfid |  |-  ( N e. NN -> ( 1 ... N ) e. Fin ) | 
						
							| 93 | 26 | a1i |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> -u 1 e. CC ) | 
						
							| 94 |  | elfznn |  |-  ( k e. ( 1 ... N ) -> k e. NN ) | 
						
							| 95 |  | nnm1nn0 |  |-  ( k e. NN -> ( k - 1 ) e. NN0 ) | 
						
							| 96 | 94 95 | syl |  |-  ( k e. ( 1 ... N ) -> ( k - 1 ) e. NN0 ) | 
						
							| 97 | 96 | adantl |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( k - 1 ) e. NN0 ) | 
						
							| 98 | 93 97 | expcld |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( -u 1 ^ ( k - 1 ) ) e. CC ) | 
						
							| 99 |  | elfzelz |  |-  ( k e. ( 1 ... N ) -> k e. ZZ ) | 
						
							| 100 |  | elfzel1 |  |-  ( k e. ( 1 ... N ) -> 1 e. ZZ ) | 
						
							| 101 | 99 100 | zsubcld |  |-  ( k e. ( 1 ... N ) -> ( k - 1 ) e. ZZ ) | 
						
							| 102 | 13 101 19 | syl2an |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( N - 1 ) _C ( k - 1 ) ) e. NN0 ) | 
						
							| 103 | 102 | nn0cnd |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( N - 1 ) _C ( k - 1 ) ) e. CC ) | 
						
							| 104 | 98 103 | mulcld |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) e. CC ) | 
						
							| 105 | 92 104 | fsumcl |  |-  ( N e. NN -> sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) e. CC ) | 
						
							| 106 | 105 | addridd |  |-  ( N e. NN -> ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + 0 ) = sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 107 | 91 106 | eqtrd |  |-  ( N e. NN -> ( sum_ j e. ( 1 ... N ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) + 0 ) = sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 108 | 66 84 107 | 3eqtrd |  |-  ( N e. NN -> sum_ j e. ( 1 ... ( N + 1 ) ) ( ( -u 1 ^ ( j - 1 ) ) x. ( ( N - 1 ) _C ( j - 1 ) ) ) = sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 109 | 42 46 108 | 3eqtrd |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) = sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 110 |  | elnn0uz |  |-  ( N e. NN0 <-> N e. ( ZZ>= ` 0 ) ) | 
						
							| 111 | 70 110 | sylib |  |-  ( N e. NN -> N e. ( ZZ>= ` 0 ) ) | 
						
							| 112 |  | oveq2 |  |-  ( k = 0 -> ( -u 1 ^ k ) = ( -u 1 ^ 0 ) ) | 
						
							| 113 |  | oveq1 |  |-  ( k = 0 -> ( k - 1 ) = ( 0 - 1 ) ) | 
						
							| 114 | 113 | oveq2d |  |-  ( k = 0 -> ( ( N - 1 ) _C ( k - 1 ) ) = ( ( N - 1 ) _C ( 0 - 1 ) ) ) | 
						
							| 115 | 112 114 | oveq12d |  |-  ( k = 0 -> ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( ( -u 1 ^ 0 ) x. ( ( N - 1 ) _C ( 0 - 1 ) ) ) ) | 
						
							| 116 | 111 34 115 | fsum1p |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( ( ( -u 1 ^ 0 ) x. ( ( N - 1 ) _C ( 0 - 1 ) ) ) + sum_ k e. ( ( 0 + 1 ) ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 117 | 27 | exp0d |  |-  ( N e. NN -> ( -u 1 ^ 0 ) = 1 ) | 
						
							| 118 |  | 0z |  |-  0 e. ZZ | 
						
							| 119 |  | zsubcl |  |-  ( ( 0 e. ZZ /\ 1 e. ZZ ) -> ( 0 - 1 ) e. ZZ ) | 
						
							| 120 | 118 30 119 | mp2an |  |-  ( 0 - 1 ) e. ZZ | 
						
							| 121 | 120 | a1i |  |-  ( N e. NN -> ( 0 - 1 ) e. ZZ ) | 
						
							| 122 |  | 0re |  |-  0 e. RR | 
						
							| 123 |  | ltm1 |  |-  ( 0 e. RR -> ( 0 - 1 ) < 0 ) | 
						
							| 124 | 122 123 | mp1i |  |-  ( N e. NN -> ( 0 - 1 ) < 0 ) | 
						
							| 125 | 124 | orcd |  |-  ( N e. NN -> ( ( 0 - 1 ) < 0 \/ ( N - 1 ) < ( 0 - 1 ) ) ) | 
						
							| 126 |  | bcval4 |  |-  ( ( ( N - 1 ) e. NN0 /\ ( 0 - 1 ) e. ZZ /\ ( ( 0 - 1 ) < 0 \/ ( N - 1 ) < ( 0 - 1 ) ) ) -> ( ( N - 1 ) _C ( 0 - 1 ) ) = 0 ) | 
						
							| 127 | 13 121 125 126 | syl3anc |  |-  ( N e. NN -> ( ( N - 1 ) _C ( 0 - 1 ) ) = 0 ) | 
						
							| 128 | 117 127 | oveq12d |  |-  ( N e. NN -> ( ( -u 1 ^ 0 ) x. ( ( N - 1 ) _C ( 0 - 1 ) ) ) = ( 1 x. 0 ) ) | 
						
							| 129 | 6 | a1i |  |-  ( N e. NN -> 1 e. CC ) | 
						
							| 130 | 129 | mul01d |  |-  ( N e. NN -> ( 1 x. 0 ) = 0 ) | 
						
							| 131 | 128 130 | eqtrd |  |-  ( N e. NN -> ( ( -u 1 ^ 0 ) x. ( ( N - 1 ) _C ( 0 - 1 ) ) ) = 0 ) | 
						
							| 132 | 43 | a1i |  |-  ( N e. NN -> ( 0 + 1 ) = 1 ) | 
						
							| 133 | 132 | oveq1d |  |-  ( N e. NN -> ( ( 0 + 1 ) ... N ) = ( 1 ... N ) ) | 
						
							| 134 | 99 | zcnd |  |-  ( k e. ( 1 ... N ) -> k e. CC ) | 
						
							| 135 |  | npcan1 |  |-  ( k e. CC -> ( ( k - 1 ) + 1 ) = k ) | 
						
							| 136 | 135 | eqcomd |  |-  ( k e. CC -> k = ( ( k - 1 ) + 1 ) ) | 
						
							| 137 | 134 136 | syl |  |-  ( k e. ( 1 ... N ) -> k = ( ( k - 1 ) + 1 ) ) | 
						
							| 138 | 137 | adantl |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> k = ( ( k - 1 ) + 1 ) ) | 
						
							| 139 | 138 | oveq2d |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( -u 1 ^ k ) = ( -u 1 ^ ( ( k - 1 ) + 1 ) ) ) | 
						
							| 140 |  | expp1 |  |-  ( ( -u 1 e. CC /\ ( k - 1 ) e. NN0 ) -> ( -u 1 ^ ( ( k - 1 ) + 1 ) ) = ( ( -u 1 ^ ( k - 1 ) ) x. -u 1 ) ) | 
						
							| 141 | 27 96 140 | syl2an |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( -u 1 ^ ( ( k - 1 ) + 1 ) ) = ( ( -u 1 ^ ( k - 1 ) ) x. -u 1 ) ) | 
						
							| 142 | 139 141 | eqtrd |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( -u 1 ^ k ) = ( ( -u 1 ^ ( k - 1 ) ) x. -u 1 ) ) | 
						
							| 143 | 142 | oveq1d |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( ( ( -u 1 ^ ( k - 1 ) ) x. -u 1 ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 144 | 98 93 | mulcomd |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( -u 1 ^ ( k - 1 ) ) x. -u 1 ) = ( -u 1 x. ( -u 1 ^ ( k - 1 ) ) ) ) | 
						
							| 145 | 144 | oveq1d |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( ( -u 1 ^ ( k - 1 ) ) x. -u 1 ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( ( -u 1 x. ( -u 1 ^ ( k - 1 ) ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 146 | 93 98 103 | mulassd |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( -u 1 x. ( -u 1 ^ ( k - 1 ) ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( -u 1 x. ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 147 | 143 145 146 | 3eqtrd |  |-  ( ( N e. NN /\ k e. ( 1 ... N ) ) -> ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( -u 1 x. ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 148 | 133 147 | sumeq12rdv |  |-  ( N e. NN -> sum_ k e. ( ( 0 + 1 ) ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = sum_ k e. ( 1 ... N ) ( -u 1 x. ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 149 | 92 27 104 | fsummulc2 |  |-  ( N e. NN -> ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = sum_ k e. ( 1 ... N ) ( -u 1 x. ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 150 | 148 149 | eqtr4d |  |-  ( N e. NN -> sum_ k e. ( ( 0 + 1 ) ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 151 | 131 150 | oveq12d |  |-  ( N e. NN -> ( ( ( -u 1 ^ 0 ) x. ( ( N - 1 ) _C ( 0 - 1 ) ) ) + sum_ k e. ( ( 0 + 1 ) ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = ( 0 + ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) ) | 
						
							| 152 | 27 105 | mulcld |  |-  ( N e. NN -> ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) e. CC ) | 
						
							| 153 | 152 | addlidd |  |-  ( N e. NN -> ( 0 + ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) = ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 154 | 116 151 153 | 3eqtrd |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) = ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 155 | 109 154 | oveq12d |  |-  ( N e. NN -> ( sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) ) | 
						
							| 156 | 35 155 | eqtrd |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C k ) ) + ( ( -u 1 ^ k ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) ) | 
						
							| 157 | 105 | mulm1d |  |-  ( N e. NN -> ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = -u sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) | 
						
							| 158 | 157 | oveq2d |  |-  ( N e. NN -> ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) = ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + -u sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) | 
						
							| 159 | 105 | negidd |  |-  ( N e. NN -> ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + -u sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) = 0 ) | 
						
							| 160 | 158 159 | eqtrd |  |-  ( N e. NN -> ( sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) + ( -u 1 x. sum_ k e. ( 1 ... N ) ( ( -u 1 ^ ( k - 1 ) ) x. ( ( N - 1 ) _C ( k - 1 ) ) ) ) ) = 0 ) | 
						
							| 161 | 24 156 160 | 3eqtrd |  |-  ( N e. NN -> sum_ k e. ( 0 ... N ) ( ( -u 1 ^ k ) x. ( N _C k ) ) = 0 ) |