| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axlowdimlem16.1 |  |-  P = ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) | 
						
							| 2 |  | axlowdimlem16.2 |  |-  Q = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) | 
						
							| 3 |  | axlowdimlem17.3 |  |-  A = ( { <. 1 , X >. , <. 2 , Y >. } u. ( ( 3 ... N ) X. { 0 } ) ) | 
						
							| 4 |  | axlowdimlem17.4 |  |-  X e. RR | 
						
							| 5 |  | axlowdimlem17.5 |  |-  Y e. RR | 
						
							| 6 |  | uzuzle23 |  |-  ( N e. ( ZZ>= ` 3 ) -> N e. ( ZZ>= ` 2 ) ) | 
						
							| 7 | 6 | ad2antrr |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> N e. ( ZZ>= ` 2 ) ) | 
						
							| 8 |  | fzss2 |  |-  ( N e. ( ZZ>= ` 2 ) -> ( 1 ... 2 ) C_ ( 1 ... N ) ) | 
						
							| 9 | 7 8 | syl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( 1 ... 2 ) C_ ( 1 ... N ) ) | 
						
							| 10 |  | simpr |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> i e. ( 1 ... 2 ) ) | 
						
							| 11 | 9 10 | sseldd |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> i e. ( 1 ... N ) ) | 
						
							| 12 |  | fznuz |  |-  ( i e. ( 1 ... 2 ) -> -. i e. ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 13 | 12 | adantl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> -. i e. ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 14 |  | 3z |  |-  3 e. ZZ | 
						
							| 15 |  | uzid |  |-  ( 3 e. ZZ -> 3 e. ( ZZ>= ` 3 ) ) | 
						
							| 16 | 14 15 | ax-mp |  |-  3 e. ( ZZ>= ` 3 ) | 
						
							| 17 |  | df-3 |  |-  3 = ( 2 + 1 ) | 
						
							| 18 | 17 | fveq2i |  |-  ( ZZ>= ` 3 ) = ( ZZ>= ` ( 2 + 1 ) ) | 
						
							| 19 | 16 18 | eleqtri |  |-  3 e. ( ZZ>= ` ( 2 + 1 ) ) | 
						
							| 20 |  | eleq1 |  |-  ( i = 3 -> ( i e. ( ZZ>= ` ( 2 + 1 ) ) <-> 3 e. ( ZZ>= ` ( 2 + 1 ) ) ) ) | 
						
							| 21 | 19 20 | mpbiri |  |-  ( i = 3 -> i e. ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 22 | 21 | necon3bi |  |-  ( -. i e. ( ZZ>= ` ( 2 + 1 ) ) -> i =/= 3 ) | 
						
							| 23 | 13 22 | syl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> i =/= 3 ) | 
						
							| 24 | 1 | axlowdimlem9 |  |-  ( ( i e. ( 1 ... N ) /\ i =/= 3 ) -> ( P ` i ) = 0 ) | 
						
							| 25 | 11 23 24 | syl2anc |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( P ` i ) = 0 ) | 
						
							| 26 |  | elfzuz |  |-  ( I e. ( 2 ... ( N - 1 ) ) -> I e. ( ZZ>= ` 2 ) ) | 
						
							| 27 | 26 | ad2antlr |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> I e. ( ZZ>= ` 2 ) ) | 
						
							| 28 |  | eluzp1p1 |  |-  ( I e. ( ZZ>= ` 2 ) -> ( I + 1 ) e. ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 29 | 27 28 | syl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( I + 1 ) e. ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 30 |  | uzss |  |-  ( ( I + 1 ) e. ( ZZ>= ` ( 2 + 1 ) ) -> ( ZZ>= ` ( I + 1 ) ) C_ ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 31 | 29 30 | syl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( ZZ>= ` ( I + 1 ) ) C_ ( ZZ>= ` ( 2 + 1 ) ) ) | 
						
							| 32 | 31 13 | ssneldd |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> -. i e. ( ZZ>= ` ( I + 1 ) ) ) | 
						
							| 33 |  | eluzelz |  |-  ( ( I + 1 ) e. ( ZZ>= ` ( 2 + 1 ) ) -> ( I + 1 ) e. ZZ ) | 
						
							| 34 | 29 33 | syl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( I + 1 ) e. ZZ ) | 
						
							| 35 |  | uzid |  |-  ( ( I + 1 ) e. ZZ -> ( I + 1 ) e. ( ZZ>= ` ( I + 1 ) ) ) | 
						
							| 36 | 34 35 | syl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( I + 1 ) e. ( ZZ>= ` ( I + 1 ) ) ) | 
						
							| 37 |  | eleq1 |  |-  ( i = ( I + 1 ) -> ( i e. ( ZZ>= ` ( I + 1 ) ) <-> ( I + 1 ) e. ( ZZ>= ` ( I + 1 ) ) ) ) | 
						
							| 38 | 36 37 | syl5ibrcom |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( i = ( I + 1 ) -> i e. ( ZZ>= ` ( I + 1 ) ) ) ) | 
						
							| 39 | 38 | necon3bd |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( -. i e. ( ZZ>= ` ( I + 1 ) ) -> i =/= ( I + 1 ) ) ) | 
						
							| 40 | 32 39 | mpd |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> i =/= ( I + 1 ) ) | 
						
							| 41 | 2 | axlowdimlem12 |  |-  ( ( i e. ( 1 ... N ) /\ i =/= ( I + 1 ) ) -> ( Q ` i ) = 0 ) | 
						
							| 42 | 11 40 41 | syl2anc |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( Q ` i ) = 0 ) | 
						
							| 43 | 25 42 | eqtr4d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( P ` i ) = ( Q ` i ) ) | 
						
							| 44 | 43 | oveq1d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( ( P ` i ) - ( A ` i ) ) = ( ( Q ` i ) - ( A ` i ) ) ) | 
						
							| 45 | 44 | oveq1d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... 2 ) ) -> ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) | 
						
							| 46 | 45 | sumeq2dv |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 1 ... 2 ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 1 ... 2 ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) | 
						
							| 47 | 1 2 | axlowdimlem16 |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 3 ... N ) ( ( P ` i ) ^ 2 ) = sum_ i e. ( 3 ... N ) ( ( Q ` i ) ^ 2 ) ) | 
						
							| 48 | 3 | fveq1i |  |-  ( A ` i ) = ( ( { <. 1 , X >. , <. 2 , Y >. } u. ( ( 3 ... N ) X. { 0 } ) ) ` i ) | 
						
							| 49 |  | axlowdimlem2 |  |-  ( ( 1 ... 2 ) i^i ( 3 ... N ) ) = (/) | 
						
							| 50 | 4 5 | axlowdimlem4 |  |-  { <. 1 , X >. , <. 2 , Y >. } : ( 1 ... 2 ) --> RR | 
						
							| 51 |  | ffn |  |-  ( { <. 1 , X >. , <. 2 , Y >. } : ( 1 ... 2 ) --> RR -> { <. 1 , X >. , <. 2 , Y >. } Fn ( 1 ... 2 ) ) | 
						
							| 52 | 50 51 | ax-mp |  |-  { <. 1 , X >. , <. 2 , Y >. } Fn ( 1 ... 2 ) | 
						
							| 53 |  | axlowdimlem1 |  |-  ( ( 3 ... N ) X. { 0 } ) : ( 3 ... N ) --> RR | 
						
							| 54 |  | ffn |  |-  ( ( ( 3 ... N ) X. { 0 } ) : ( 3 ... N ) --> RR -> ( ( 3 ... N ) X. { 0 } ) Fn ( 3 ... N ) ) | 
						
							| 55 | 53 54 | ax-mp |  |-  ( ( 3 ... N ) X. { 0 } ) Fn ( 3 ... N ) | 
						
							| 56 |  | fvun2 |  |-  ( ( { <. 1 , X >. , <. 2 , Y >. } Fn ( 1 ... 2 ) /\ ( ( 3 ... N ) X. { 0 } ) Fn ( 3 ... N ) /\ ( ( ( 1 ... 2 ) i^i ( 3 ... N ) ) = (/) /\ i e. ( 3 ... N ) ) ) -> ( ( { <. 1 , X >. , <. 2 , Y >. } u. ( ( 3 ... N ) X. { 0 } ) ) ` i ) = ( ( ( 3 ... N ) X. { 0 } ) ` i ) ) | 
						
							| 57 | 52 55 56 | mp3an12 |  |-  ( ( ( ( 1 ... 2 ) i^i ( 3 ... N ) ) = (/) /\ i e. ( 3 ... N ) ) -> ( ( { <. 1 , X >. , <. 2 , Y >. } u. ( ( 3 ... N ) X. { 0 } ) ) ` i ) = ( ( ( 3 ... N ) X. { 0 } ) ` i ) ) | 
						
							| 58 | 49 57 | mpan |  |-  ( i e. ( 3 ... N ) -> ( ( { <. 1 , X >. , <. 2 , Y >. } u. ( ( 3 ... N ) X. { 0 } ) ) ` i ) = ( ( ( 3 ... N ) X. { 0 } ) ` i ) ) | 
						
							| 59 | 48 58 | eqtrid |  |-  ( i e. ( 3 ... N ) -> ( A ` i ) = ( ( ( 3 ... N ) X. { 0 } ) ` i ) ) | 
						
							| 60 |  | c0ex |  |-  0 e. _V | 
						
							| 61 | 60 | fvconst2 |  |-  ( i e. ( 3 ... N ) -> ( ( ( 3 ... N ) X. { 0 } ) ` i ) = 0 ) | 
						
							| 62 | 59 61 | eqtrd |  |-  ( i e. ( 3 ... N ) -> ( A ` i ) = 0 ) | 
						
							| 63 | 62 | adantl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( A ` i ) = 0 ) | 
						
							| 64 | 63 | oveq2d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( P ` i ) - ( A ` i ) ) = ( ( P ` i ) - 0 ) ) | 
						
							| 65 | 1 | axlowdimlem7 |  |-  ( N e. ( ZZ>= ` 3 ) -> P e. ( EE ` N ) ) | 
						
							| 66 | 65 | ad2antrr |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> P e. ( EE ` N ) ) | 
						
							| 67 |  | 3nn |  |-  3 e. NN | 
						
							| 68 |  | nnuz |  |-  NN = ( ZZ>= ` 1 ) | 
						
							| 69 | 67 68 | eleqtri |  |-  3 e. ( ZZ>= ` 1 ) | 
						
							| 70 |  | fzss1 |  |-  ( 3 e. ( ZZ>= ` 1 ) -> ( 3 ... N ) C_ ( 1 ... N ) ) | 
						
							| 71 | 69 70 | ax-mp |  |-  ( 3 ... N ) C_ ( 1 ... N ) | 
						
							| 72 | 71 | sseli |  |-  ( i e. ( 3 ... N ) -> i e. ( 1 ... N ) ) | 
						
							| 73 | 72 | adantl |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> i e. ( 1 ... N ) ) | 
						
							| 74 |  | fveecn |  |-  ( ( P e. ( EE ` N ) /\ i e. ( 1 ... N ) ) -> ( P ` i ) e. CC ) | 
						
							| 75 | 66 73 74 | syl2anc |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( P ` i ) e. CC ) | 
						
							| 76 | 75 | subid1d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( P ` i ) - 0 ) = ( P ` i ) ) | 
						
							| 77 | 64 76 | eqtrd |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( P ` i ) - ( A ` i ) ) = ( P ` i ) ) | 
						
							| 78 | 77 | oveq1d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = ( ( P ` i ) ^ 2 ) ) | 
						
							| 79 | 78 | sumeq2dv |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 3 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 3 ... N ) ( ( P ` i ) ^ 2 ) ) | 
						
							| 80 | 63 | oveq2d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( Q ` i ) - ( A ` i ) ) = ( ( Q ` i ) - 0 ) ) | 
						
							| 81 |  | eluzge3nn |  |-  ( N e. ( ZZ>= ` 3 ) -> N e. NN ) | 
						
							| 82 |  | 2eluzge1 |  |-  2 e. ( ZZ>= ` 1 ) | 
						
							| 83 |  | fzss1 |  |-  ( 2 e. ( ZZ>= ` 1 ) -> ( 2 ... ( N - 1 ) ) C_ ( 1 ... ( N - 1 ) ) ) | 
						
							| 84 | 82 83 | ax-mp |  |-  ( 2 ... ( N - 1 ) ) C_ ( 1 ... ( N - 1 ) ) | 
						
							| 85 | 84 | sseli |  |-  ( I e. ( 2 ... ( N - 1 ) ) -> I e. ( 1 ... ( N - 1 ) ) ) | 
						
							| 86 | 2 | axlowdimlem10 |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> Q e. ( EE ` N ) ) | 
						
							| 87 | 81 85 86 | syl2an |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> Q e. ( EE ` N ) ) | 
						
							| 88 |  | fveecn |  |-  ( ( Q e. ( EE ` N ) /\ i e. ( 1 ... N ) ) -> ( Q ` i ) e. CC ) | 
						
							| 89 | 87 72 88 | syl2an |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( Q ` i ) e. CC ) | 
						
							| 90 | 89 | subid1d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( Q ` i ) - 0 ) = ( Q ` i ) ) | 
						
							| 91 | 80 90 | eqtrd |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( Q ` i ) - ( A ` i ) ) = ( Q ` i ) ) | 
						
							| 92 | 91 | oveq1d |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 3 ... N ) ) -> ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) = ( ( Q ` i ) ^ 2 ) ) | 
						
							| 93 | 92 | sumeq2dv |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 3 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 3 ... N ) ( ( Q ` i ) ^ 2 ) ) | 
						
							| 94 | 47 79 93 | 3eqtr4d |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 3 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 3 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) | 
						
							| 95 | 46 94 | oveq12d |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( sum_ i e. ( 1 ... 2 ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) + sum_ i e. ( 3 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) ) = ( sum_ i e. ( 1 ... 2 ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) + sum_ i e. ( 3 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) ) | 
						
							| 96 | 49 | a1i |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( ( 1 ... 2 ) i^i ( 3 ... N ) ) = (/) ) | 
						
							| 97 |  | eluzelre |  |-  ( N e. ( ZZ>= ` 3 ) -> N e. RR ) | 
						
							| 98 |  | eluzle |  |-  ( N e. ( ZZ>= ` 3 ) -> 3 <_ N ) | 
						
							| 99 |  | 2re |  |-  2 e. RR | 
						
							| 100 |  | 3re |  |-  3 e. RR | 
						
							| 101 |  | 2lt3 |  |-  2 < 3 | 
						
							| 102 | 99 100 101 | ltleii |  |-  2 <_ 3 | 
						
							| 103 |  | letr |  |-  ( ( 2 e. RR /\ 3 e. RR /\ N e. RR ) -> ( ( 2 <_ 3 /\ 3 <_ N ) -> 2 <_ N ) ) | 
						
							| 104 | 99 100 103 | mp3an12 |  |-  ( N e. RR -> ( ( 2 <_ 3 /\ 3 <_ N ) -> 2 <_ N ) ) | 
						
							| 105 | 102 104 | mpani |  |-  ( N e. RR -> ( 3 <_ N -> 2 <_ N ) ) | 
						
							| 106 | 97 98 105 | sylc |  |-  ( N e. ( ZZ>= ` 3 ) -> 2 <_ N ) | 
						
							| 107 |  | 1le2 |  |-  1 <_ 2 | 
						
							| 108 | 106 107 | jctil |  |-  ( N e. ( ZZ>= ` 3 ) -> ( 1 <_ 2 /\ 2 <_ N ) ) | 
						
							| 109 | 108 | adantr |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( 1 <_ 2 /\ 2 <_ N ) ) | 
						
							| 110 |  | eluzelz |  |-  ( N e. ( ZZ>= ` 3 ) -> N e. ZZ ) | 
						
							| 111 | 110 | adantr |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> N e. ZZ ) | 
						
							| 112 |  | 2z |  |-  2 e. ZZ | 
						
							| 113 |  | 1z |  |-  1 e. ZZ | 
						
							| 114 |  | elfz |  |-  ( ( 2 e. ZZ /\ 1 e. ZZ /\ N e. ZZ ) -> ( 2 e. ( 1 ... N ) <-> ( 1 <_ 2 /\ 2 <_ N ) ) ) | 
						
							| 115 | 112 113 114 | mp3an12 |  |-  ( N e. ZZ -> ( 2 e. ( 1 ... N ) <-> ( 1 <_ 2 /\ 2 <_ N ) ) ) | 
						
							| 116 | 111 115 | syl |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( 2 e. ( 1 ... N ) <-> ( 1 <_ 2 /\ 2 <_ N ) ) ) | 
						
							| 117 | 109 116 | mpbird |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> 2 e. ( 1 ... N ) ) | 
						
							| 118 |  | fzsplit |  |-  ( 2 e. ( 1 ... N ) -> ( 1 ... N ) = ( ( 1 ... 2 ) u. ( ( 2 + 1 ) ... N ) ) ) | 
						
							| 119 | 117 118 | syl |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( 1 ... N ) = ( ( 1 ... 2 ) u. ( ( 2 + 1 ) ... N ) ) ) | 
						
							| 120 | 17 | oveq1i |  |-  ( 3 ... N ) = ( ( 2 + 1 ) ... N ) | 
						
							| 121 | 120 | uneq2i |  |-  ( ( 1 ... 2 ) u. ( 3 ... N ) ) = ( ( 1 ... 2 ) u. ( ( 2 + 1 ) ... N ) ) | 
						
							| 122 | 119 121 | eqtr4di |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( 1 ... N ) = ( ( 1 ... 2 ) u. ( 3 ... N ) ) ) | 
						
							| 123 |  | fzfid |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( 1 ... N ) e. Fin ) | 
						
							| 124 | 65 | ad2antrr |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> P e. ( EE ` N ) ) | 
						
							| 125 | 124 74 | sylancom |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( P ` i ) e. CC ) | 
						
							| 126 | 4 5 | axlowdimlem5 |  |-  ( N e. ( ZZ>= ` 2 ) -> ( { <. 1 , X >. , <. 2 , Y >. } u. ( ( 3 ... N ) X. { 0 } ) ) e. ( EE ` N ) ) | 
						
							| 127 | 3 126 | eqeltrid |  |-  ( N e. ( ZZ>= ` 2 ) -> A e. ( EE ` N ) ) | 
						
							| 128 | 6 127 | syl |  |-  ( N e. ( ZZ>= ` 3 ) -> A e. ( EE ` N ) ) | 
						
							| 129 | 128 | ad2antrr |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> A e. ( EE ` N ) ) | 
						
							| 130 |  | fveecn |  |-  ( ( A e. ( EE ` N ) /\ i e. ( 1 ... N ) ) -> ( A ` i ) e. CC ) | 
						
							| 131 | 129 130 | sylancom |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( A ` i ) e. CC ) | 
						
							| 132 | 125 131 | subcld |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( ( P ` i ) - ( A ` i ) ) e. CC ) | 
						
							| 133 | 132 | sqcld |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) e. CC ) | 
						
							| 134 | 96 122 123 133 | fsumsplit |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 1 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = ( sum_ i e. ( 1 ... 2 ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) + sum_ i e. ( 3 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) ) ) | 
						
							| 135 | 87 88 | sylan |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( Q ` i ) e. CC ) | 
						
							| 136 | 135 131 | subcld |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( ( Q ` i ) - ( A ` i ) ) e. CC ) | 
						
							| 137 | 136 | sqcld |  |-  ( ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) /\ i e. ( 1 ... N ) ) -> ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) e. CC ) | 
						
							| 138 | 96 122 123 137 | fsumsplit |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 1 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) = ( sum_ i e. ( 1 ... 2 ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) + sum_ i e. ( 3 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) ) | 
						
							| 139 | 95 134 138 | 3eqtr4d |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> sum_ i e. ( 1 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 1 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) | 
						
							| 140 | 65 | adantr |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> P e. ( EE ` N ) ) | 
						
							| 141 | 128 | adantr |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> A e. ( EE ` N ) ) | 
						
							| 142 |  | brcgr |  |-  ( ( ( P e. ( EE ` N ) /\ A e. ( EE ` N ) ) /\ ( Q e. ( EE ` N ) /\ A e. ( EE ` N ) ) ) -> ( <. P , A >. Cgr <. Q , A >. <-> sum_ i e. ( 1 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 1 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) ) | 
						
							| 143 | 140 141 87 141 142 | syl22anc |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> ( <. P , A >. Cgr <. Q , A >. <-> sum_ i e. ( 1 ... N ) ( ( ( P ` i ) - ( A ` i ) ) ^ 2 ) = sum_ i e. ( 1 ... N ) ( ( ( Q ` i ) - ( A ` i ) ) ^ 2 ) ) ) | 
						
							| 144 | 139 143 | mpbird |  |-  ( ( N e. ( ZZ>= ` 3 ) /\ I e. ( 2 ... ( N - 1 ) ) ) -> <. P , A >. Cgr <. Q , A >. ) |