| Step | Hyp | Ref | Expression | 
						
							| 1 |  | aaliou3lem.c |  |-  F = ( a e. NN |-> ( 2 ^ -u ( ! ` a ) ) ) | 
						
							| 2 |  | aaliou3lem.d |  |-  L = sum_ b e. NN ( F ` b ) | 
						
							| 3 |  | aaliou3lem.e |  |-  H = ( c e. NN |-> sum_ b e. ( 1 ... c ) ( F ` b ) ) | 
						
							| 4 |  | peano2nn |  |-  ( A e. NN -> ( A + 1 ) e. NN ) | 
						
							| 5 |  | eqid |  |-  ( c e. ( ZZ>= ` ( A + 1 ) ) |-> ( ( 2 ^ -u ( ! ` ( A + 1 ) ) ) x. ( ( 1 / 2 ) ^ ( c - ( A + 1 ) ) ) ) ) = ( c e. ( ZZ>= ` ( A + 1 ) ) |-> ( ( 2 ^ -u ( ! ` ( A + 1 ) ) ) x. ( ( 1 / 2 ) ^ ( c - ( A + 1 ) ) ) ) ) | 
						
							| 6 | 5 1 | aaliou3lem3 |  |-  ( ( A + 1 ) e. NN -> ( seq ( A + 1 ) ( + , F ) e. dom ~~> /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) | 
						
							| 7 |  | 3simpc |  |-  ( ( seq ( A + 1 ) ( + , F ) e. dom ~~> /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) -> ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) | 
						
							| 8 | 4 6 7 | 3syl |  |-  ( A e. NN -> ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) | 
						
							| 9 |  | nncn |  |-  ( A e. NN -> A e. CC ) | 
						
							| 10 |  | ax-1cn |  |-  1 e. CC | 
						
							| 11 |  | pncan |  |-  ( ( A e. CC /\ 1 e. CC ) -> ( ( A + 1 ) - 1 ) = A ) | 
						
							| 12 | 9 10 11 | sylancl |  |-  ( A e. NN -> ( ( A + 1 ) - 1 ) = A ) | 
						
							| 13 | 12 | oveq2d |  |-  ( A e. NN -> ( 1 ... ( ( A + 1 ) - 1 ) ) = ( 1 ... A ) ) | 
						
							| 14 | 13 | sumeq1d |  |-  ( A e. NN -> sum_ b e. ( 1 ... ( ( A + 1 ) - 1 ) ) ( F ` b ) = sum_ b e. ( 1 ... A ) ( F ` b ) ) | 
						
							| 15 | 14 | oveq1d |  |-  ( A e. NN -> ( sum_ b e. ( 1 ... ( ( A + 1 ) - 1 ) ) ( F ` b ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) = ( sum_ b e. ( 1 ... A ) ( F ` b ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) ) | 
						
							| 16 |  | nnuz |  |-  NN = ( ZZ>= ` 1 ) | 
						
							| 17 |  | eqid |  |-  ( ZZ>= ` ( A + 1 ) ) = ( ZZ>= ` ( A + 1 ) ) | 
						
							| 18 |  | eqidd |  |-  ( ( A e. NN /\ b e. NN ) -> ( F ` b ) = ( F ` b ) ) | 
						
							| 19 |  | fveq2 |  |-  ( a = b -> ( ! ` a ) = ( ! ` b ) ) | 
						
							| 20 | 19 | negeqd |  |-  ( a = b -> -u ( ! ` a ) = -u ( ! ` b ) ) | 
						
							| 21 | 20 | oveq2d |  |-  ( a = b -> ( 2 ^ -u ( ! ` a ) ) = ( 2 ^ -u ( ! ` b ) ) ) | 
						
							| 22 |  | ovex |  |-  ( 2 ^ -u ( ! ` b ) ) e. _V | 
						
							| 23 | 21 1 22 | fvmpt |  |-  ( b e. NN -> ( F ` b ) = ( 2 ^ -u ( ! ` b ) ) ) | 
						
							| 24 |  | 2rp |  |-  2 e. RR+ | 
						
							| 25 |  | nnnn0 |  |-  ( b e. NN -> b e. NN0 ) | 
						
							| 26 |  | faccl |  |-  ( b e. NN0 -> ( ! ` b ) e. NN ) | 
						
							| 27 | 25 26 | syl |  |-  ( b e. NN -> ( ! ` b ) e. NN ) | 
						
							| 28 | 27 | nnzd |  |-  ( b e. NN -> ( ! ` b ) e. ZZ ) | 
						
							| 29 | 28 | znegcld |  |-  ( b e. NN -> -u ( ! ` b ) e. ZZ ) | 
						
							| 30 |  | rpexpcl |  |-  ( ( 2 e. RR+ /\ -u ( ! ` b ) e. ZZ ) -> ( 2 ^ -u ( ! ` b ) ) e. RR+ ) | 
						
							| 31 | 24 29 30 | sylancr |  |-  ( b e. NN -> ( 2 ^ -u ( ! ` b ) ) e. RR+ ) | 
						
							| 32 | 31 | rpcnd |  |-  ( b e. NN -> ( 2 ^ -u ( ! ` b ) ) e. CC ) | 
						
							| 33 | 23 32 | eqeltrd |  |-  ( b e. NN -> ( F ` b ) e. CC ) | 
						
							| 34 | 33 | adantl |  |-  ( ( A e. NN /\ b e. NN ) -> ( F ` b ) e. CC ) | 
						
							| 35 |  | 1nn |  |-  1 e. NN | 
						
							| 36 |  | eqid |  |-  ( c e. ( ZZ>= ` 1 ) |-> ( ( 2 ^ -u ( ! ` 1 ) ) x. ( ( 1 / 2 ) ^ ( c - 1 ) ) ) ) = ( c e. ( ZZ>= ` 1 ) |-> ( ( 2 ^ -u ( ! ` 1 ) ) x. ( ( 1 / 2 ) ^ ( c - 1 ) ) ) ) | 
						
							| 37 | 36 1 | aaliou3lem3 |  |-  ( 1 e. NN -> ( seq 1 ( + , F ) e. dom ~~> /\ sum_ b e. ( ZZ>= ` 1 ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` 1 ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` 1 ) ) ) ) ) | 
						
							| 38 | 37 | simp1d |  |-  ( 1 e. NN -> seq 1 ( + , F ) e. dom ~~> ) | 
						
							| 39 | 35 38 | mp1i |  |-  ( A e. NN -> seq 1 ( + , F ) e. dom ~~> ) | 
						
							| 40 | 16 17 4 18 34 39 | isumsplit |  |-  ( A e. NN -> sum_ b e. NN ( F ` b ) = ( sum_ b e. ( 1 ... ( ( A + 1 ) - 1 ) ) ( F ` b ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) ) | 
						
							| 41 |  | oveq2 |  |-  ( c = A -> ( 1 ... c ) = ( 1 ... A ) ) | 
						
							| 42 | 41 | sumeq1d |  |-  ( c = A -> sum_ b e. ( 1 ... c ) ( F ` b ) = sum_ b e. ( 1 ... A ) ( F ` b ) ) | 
						
							| 43 |  | sumex |  |-  sum_ b e. ( 1 ... A ) ( F ` b ) e. _V | 
						
							| 44 | 42 3 43 | fvmpt |  |-  ( A e. NN -> ( H ` A ) = sum_ b e. ( 1 ... A ) ( F ` b ) ) | 
						
							| 45 | 44 | oveq1d |  |-  ( A e. NN -> ( ( H ` A ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) = ( sum_ b e. ( 1 ... A ) ( F ` b ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) ) | 
						
							| 46 | 15 40 45 | 3eqtr4rd |  |-  ( A e. NN -> ( ( H ` A ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) = sum_ b e. NN ( F ` b ) ) | 
						
							| 47 | 46 2 | eqtr4di |  |-  ( A e. NN -> ( ( H ` A ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) = L ) | 
						
							| 48 | 1 2 3 | aaliou3lem4 |  |-  L e. RR | 
						
							| 49 | 48 | recni |  |-  L e. CC | 
						
							| 50 | 49 | a1i |  |-  ( A e. NN -> L e. CC ) | 
						
							| 51 | 1 2 3 | aaliou3lem5 |  |-  ( A e. NN -> ( H ` A ) e. RR ) | 
						
							| 52 | 51 | recnd |  |-  ( A e. NN -> ( H ` A ) e. CC ) | 
						
							| 53 | 6 | simp2d |  |-  ( ( A + 1 ) e. NN -> sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ ) | 
						
							| 54 | 4 53 | syl |  |-  ( A e. NN -> sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ ) | 
						
							| 55 | 54 | rpcnd |  |-  ( A e. NN -> sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. CC ) | 
						
							| 56 | 50 52 55 | subaddd |  |-  ( A e. NN -> ( ( L - ( H ` A ) ) = sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <-> ( ( H ` A ) + sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) = L ) ) | 
						
							| 57 | 47 56 | mpbird |  |-  ( A e. NN -> ( L - ( H ` A ) ) = sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) ) | 
						
							| 58 | 57 | eqcomd |  |-  ( A e. NN -> sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) = ( L - ( H ` A ) ) ) | 
						
							| 59 |  | eleq1 |  |-  ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) = ( L - ( H ` A ) ) -> ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ <-> ( L - ( H ` A ) ) e. RR+ ) ) | 
						
							| 60 |  | breq1 |  |-  ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) = ( L - ( H ` A ) ) -> ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) <-> ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) | 
						
							| 61 | 59 60 | anbi12d |  |-  ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) = ( L - ( H ` A ) ) -> ( ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) <-> ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) ) | 
						
							| 62 | 58 61 | syl |  |-  ( A e. NN -> ( ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) <-> ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) ) | 
						
							| 63 | 51 | adantr |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( H ` A ) e. RR ) | 
						
							| 64 |  | simprl |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( L - ( H ` A ) ) e. RR+ ) | 
						
							| 65 |  | difrp |  |-  ( ( ( H ` A ) e. RR /\ L e. RR ) -> ( ( H ` A ) < L <-> ( L - ( H ` A ) ) e. RR+ ) ) | 
						
							| 66 | 63 48 65 | sylancl |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( H ` A ) < L <-> ( L - ( H ` A ) ) e. RR+ ) ) | 
						
							| 67 | 64 66 | mpbird |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( H ` A ) < L ) | 
						
							| 68 | 63 67 | ltned |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( H ` A ) =/= L ) | 
						
							| 69 |  | nnnn0 |  |-  ( ( A + 1 ) e. NN -> ( A + 1 ) e. NN0 ) | 
						
							| 70 |  | faccl |  |-  ( ( A + 1 ) e. NN0 -> ( ! ` ( A + 1 ) ) e. NN ) | 
						
							| 71 | 4 69 70 | 3syl |  |-  ( A e. NN -> ( ! ` ( A + 1 ) ) e. NN ) | 
						
							| 72 | 71 | nnzd |  |-  ( A e. NN -> ( ! ` ( A + 1 ) ) e. ZZ ) | 
						
							| 73 | 72 | znegcld |  |-  ( A e. NN -> -u ( ! ` ( A + 1 ) ) e. ZZ ) | 
						
							| 74 |  | rpexpcl |  |-  ( ( 2 e. RR+ /\ -u ( ! ` ( A + 1 ) ) e. ZZ ) -> ( 2 ^ -u ( ! ` ( A + 1 ) ) ) e. RR+ ) | 
						
							| 75 | 24 73 74 | sylancr |  |-  ( A e. NN -> ( 2 ^ -u ( ! ` ( A + 1 ) ) ) e. RR+ ) | 
						
							| 76 |  | rpmulcl |  |-  ( ( 2 e. RR+ /\ ( 2 ^ -u ( ! ` ( A + 1 ) ) ) e. RR+ ) -> ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) e. RR+ ) | 
						
							| 77 | 24 75 76 | sylancr |  |-  ( A e. NN -> ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) e. RR+ ) | 
						
							| 78 | 77 | adantr |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) e. RR+ ) | 
						
							| 79 | 78 | rpred |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) e. RR ) | 
						
							| 80 | 63 79 | resubcld |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( H ` A ) - ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) e. RR ) | 
						
							| 81 | 48 | a1i |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> L e. RR ) | 
						
							| 82 | 63 78 | ltsubrpd |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( H ` A ) - ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) < ( H ` A ) ) | 
						
							| 83 | 80 63 81 82 67 | lttrd |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( H ` A ) - ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) < L ) | 
						
							| 84 | 80 81 83 | ltled |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( H ` A ) - ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) <_ L ) | 
						
							| 85 |  | simprr |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) | 
						
							| 86 | 81 63 79 | lesubadd2d |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) <-> L <_ ( ( H ` A ) + ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) ) | 
						
							| 87 | 85 86 | mpbid |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> L <_ ( ( H ` A ) + ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) | 
						
							| 88 | 81 63 79 | absdifled |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( abs ` ( L - ( H ` A ) ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) <-> ( ( ( H ` A ) - ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) <_ L /\ L <_ ( ( H ` A ) + ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) ) ) | 
						
							| 89 | 84 87 88 | mpbir2and |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( abs ` ( L - ( H ` A ) ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) | 
						
							| 90 | 68 89 | jca |  |-  ( ( A e. NN /\ ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) -> ( ( H ` A ) =/= L /\ ( abs ` ( L - ( H ` A ) ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) | 
						
							| 91 | 90 | ex |  |-  ( A e. NN -> ( ( ( L - ( H ` A ) ) e. RR+ /\ ( L - ( H ` A ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) -> ( ( H ` A ) =/= L /\ ( abs ` ( L - ( H ` A ) ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) ) | 
						
							| 92 | 62 91 | sylbid |  |-  ( A e. NN -> ( ( sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) e. RR+ /\ sum_ b e. ( ZZ>= ` ( A + 1 ) ) ( F ` b ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) -> ( ( H ` A ) =/= L /\ ( abs ` ( L - ( H ` A ) ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) ) | 
						
							| 93 | 8 92 | mpd |  |-  ( A e. NN -> ( ( H ` A ) =/= L /\ ( abs ` ( L - ( H ` A ) ) ) <_ ( 2 x. ( 2 ^ -u ( ! ` ( A + 1 ) ) ) ) ) ) |