| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dipfval.1 |  |-  X = ( BaseSet ` U ) | 
						
							| 2 |  | dipfval.2 |  |-  G = ( +v ` U ) | 
						
							| 3 |  | dipfval.4 |  |-  S = ( .sOLD ` U ) | 
						
							| 4 |  | dipfval.6 |  |-  N = ( normCV ` U ) | 
						
							| 5 |  | dipfval.7 |  |-  P = ( .iOLD ` U ) | 
						
							| 6 | 1 2 3 4 5 | ipval |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( A P B ) = ( sum_ k e. ( 1 ... 4 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) / 4 ) ) | 
						
							| 7 |  | ax-icn |  |-  _i e. CC | 
						
							| 8 | 1 2 3 4 5 | ipval2lem4 |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ _i e. CC ) -> ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 9 | 7 8 | mpan2 |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 10 |  | mulcl |  |-  ( ( _i e. CC /\ ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) e. CC ) -> ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 11 | 7 9 10 | sylancr |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 12 |  | neg1cn |  |-  -u 1 e. CC | 
						
							| 13 | 1 2 3 4 5 | ipval2lem4 |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ -u 1 e. CC ) -> ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 14 | 12 13 | mpan2 |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 15 | 11 14 | subcld |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 16 |  | negicn |  |-  -u _i e. CC | 
						
							| 17 | 1 2 3 4 5 | ipval2lem4 |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ -u _i e. CC ) -> ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 18 | 16 17 | mpan2 |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 19 |  | mulcl |  |-  ( ( _i e. CC /\ ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) e. CC ) -> ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 20 | 7 18 19 | sylancr |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 21 | 15 20 | negsubd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + -u ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 22 | 14 | mulm1d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) = -u ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) | 
						
							| 23 | 22 | oveq2d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + -u ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 24 | 11 14 | negsubd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + -u ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 25 | 23 24 | eqtrd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 26 |  | mulneg1 |  |-  ( ( _i e. CC /\ ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) e. CC ) -> ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) = -u ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) | 
						
							| 27 | 7 18 26 | sylancr |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) = -u ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) | 
						
							| 28 | 25 27 | oveq12d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + -u ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 29 |  | subdi |  |-  ( ( _i e. CC /\ ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) e. CC /\ ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) e. CC ) -> ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 30 | 7 29 | mp3an1 |  |-  ( ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) e. CC /\ ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) e. CC ) -> ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 31 | 9 18 30 | syl2anc |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 32 | 31 | oveq1d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 33 | 11 20 14 | sub32d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 34 | 32 33 | eqtrd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) - ( _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 35 | 21 28 34 | 3eqtr4d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 36 | 1 3 | nvsid |  |-  ( ( U e. NrmCVec /\ B e. X ) -> ( 1 S B ) = B ) | 
						
							| 37 | 36 | oveq2d |  |-  ( ( U e. NrmCVec /\ B e. X ) -> ( A G ( 1 S B ) ) = ( A G B ) ) | 
						
							| 38 | 37 | fveq2d |  |-  ( ( U e. NrmCVec /\ B e. X ) -> ( N ` ( A G ( 1 S B ) ) ) = ( N ` ( A G B ) ) ) | 
						
							| 39 | 38 | oveq1d |  |-  ( ( U e. NrmCVec /\ B e. X ) -> ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) = ( ( N ` ( A G B ) ) ^ 2 ) ) | 
						
							| 40 | 39 | 3adant2 |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) = ( ( N ` ( A G B ) ) ^ 2 ) ) | 
						
							| 41 | 40 | oveq2d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) = ( 1 x. ( ( N ` ( A G B ) ) ^ 2 ) ) ) | 
						
							| 42 | 1 2 3 4 5 | ipval2lem3 |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( N ` ( A G B ) ) ^ 2 ) e. RR ) | 
						
							| 43 | 42 | recnd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( N ` ( A G B ) ) ^ 2 ) e. CC ) | 
						
							| 44 | 43 | mullidd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 1 x. ( ( N ` ( A G B ) ) ^ 2 ) ) = ( ( N ` ( A G B ) ) ^ 2 ) ) | 
						
							| 45 | 41 44 | eqtrd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) = ( ( N ` ( A G B ) ) ^ 2 ) ) | 
						
							| 46 | 35 45 | oveq12d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) ) = ( ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( ( N ` ( A G B ) ) ^ 2 ) ) ) | 
						
							| 47 |  | nnuz |  |-  NN = ( ZZ>= ` 1 ) | 
						
							| 48 |  | df-4 |  |-  4 = ( 3 + 1 ) | 
						
							| 49 |  | oveq2 |  |-  ( k = 4 -> ( _i ^ k ) = ( _i ^ 4 ) ) | 
						
							| 50 |  | i4 |  |-  ( _i ^ 4 ) = 1 | 
						
							| 51 | 49 50 | eqtrdi |  |-  ( k = 4 -> ( _i ^ k ) = 1 ) | 
						
							| 52 | 51 | oveq1d |  |-  ( k = 4 -> ( ( _i ^ k ) S B ) = ( 1 S B ) ) | 
						
							| 53 | 52 | oveq2d |  |-  ( k = 4 -> ( A G ( ( _i ^ k ) S B ) ) = ( A G ( 1 S B ) ) ) | 
						
							| 54 | 53 | fveq2d |  |-  ( k = 4 -> ( N ` ( A G ( ( _i ^ k ) S B ) ) ) = ( N ` ( A G ( 1 S B ) ) ) ) | 
						
							| 55 | 54 | oveq1d |  |-  ( k = 4 -> ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) = ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) | 
						
							| 56 | 51 55 | oveq12d |  |-  ( k = 4 -> ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 57 |  | nnnn0 |  |-  ( k e. NN -> k e. NN0 ) | 
						
							| 58 |  | expcl |  |-  ( ( _i e. CC /\ k e. NN0 ) -> ( _i ^ k ) e. CC ) | 
						
							| 59 | 7 57 58 | sylancr |  |-  ( k e. NN -> ( _i ^ k ) e. CC ) | 
						
							| 60 | 59 | adantl |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ k e. NN ) -> ( _i ^ k ) e. CC ) | 
						
							| 61 | 1 2 3 4 5 | ipval2lem4 |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ ( _i ^ k ) e. CC ) -> ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 62 | 59 61 | sylan2 |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ k e. NN ) -> ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) e. CC ) | 
						
							| 63 | 60 62 | mulcld |  |-  ( ( ( U e. NrmCVec /\ A e. X /\ B e. X ) /\ k e. NN ) -> ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 64 |  | df-3 |  |-  3 = ( 2 + 1 ) | 
						
							| 65 |  | oveq2 |  |-  ( k = 3 -> ( _i ^ k ) = ( _i ^ 3 ) ) | 
						
							| 66 |  | i3 |  |-  ( _i ^ 3 ) = -u _i | 
						
							| 67 | 65 66 | eqtrdi |  |-  ( k = 3 -> ( _i ^ k ) = -u _i ) | 
						
							| 68 | 67 | oveq1d |  |-  ( k = 3 -> ( ( _i ^ k ) S B ) = ( -u _i S B ) ) | 
						
							| 69 | 68 | oveq2d |  |-  ( k = 3 -> ( A G ( ( _i ^ k ) S B ) ) = ( A G ( -u _i S B ) ) ) | 
						
							| 70 | 69 | fveq2d |  |-  ( k = 3 -> ( N ` ( A G ( ( _i ^ k ) S B ) ) ) = ( N ` ( A G ( -u _i S B ) ) ) ) | 
						
							| 71 | 70 | oveq1d |  |-  ( k = 3 -> ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) = ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) | 
						
							| 72 | 67 71 | oveq12d |  |-  ( k = 3 -> ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) | 
						
							| 73 |  | df-2 |  |-  2 = ( 1 + 1 ) | 
						
							| 74 |  | oveq2 |  |-  ( k = 2 -> ( _i ^ k ) = ( _i ^ 2 ) ) | 
						
							| 75 |  | i2 |  |-  ( _i ^ 2 ) = -u 1 | 
						
							| 76 | 74 75 | eqtrdi |  |-  ( k = 2 -> ( _i ^ k ) = -u 1 ) | 
						
							| 77 | 76 | oveq1d |  |-  ( k = 2 -> ( ( _i ^ k ) S B ) = ( -u 1 S B ) ) | 
						
							| 78 | 77 | oveq2d |  |-  ( k = 2 -> ( A G ( ( _i ^ k ) S B ) ) = ( A G ( -u 1 S B ) ) ) | 
						
							| 79 | 78 | fveq2d |  |-  ( k = 2 -> ( N ` ( A G ( ( _i ^ k ) S B ) ) ) = ( N ` ( A G ( -u 1 S B ) ) ) ) | 
						
							| 80 | 79 | oveq1d |  |-  ( k = 2 -> ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) = ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) | 
						
							| 81 | 76 80 | oveq12d |  |-  ( k = 2 -> ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) | 
						
							| 82 |  | 1z |  |-  1 e. ZZ | 
						
							| 83 |  | oveq2 |  |-  ( k = 1 -> ( _i ^ k ) = ( _i ^ 1 ) ) | 
						
							| 84 |  | exp1 |  |-  ( _i e. CC -> ( _i ^ 1 ) = _i ) | 
						
							| 85 | 7 84 | ax-mp |  |-  ( _i ^ 1 ) = _i | 
						
							| 86 | 83 85 | eqtrdi |  |-  ( k = 1 -> ( _i ^ k ) = _i ) | 
						
							| 87 | 86 | oveq1d |  |-  ( k = 1 -> ( ( _i ^ k ) S B ) = ( _i S B ) ) | 
						
							| 88 | 87 | oveq2d |  |-  ( k = 1 -> ( A G ( ( _i ^ k ) S B ) ) = ( A G ( _i S B ) ) ) | 
						
							| 89 | 88 | fveq2d |  |-  ( k = 1 -> ( N ` ( A G ( ( _i ^ k ) S B ) ) ) = ( N ` ( A G ( _i S B ) ) ) ) | 
						
							| 90 | 89 | oveq1d |  |-  ( k = 1 -> ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) = ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) | 
						
							| 91 | 86 90 | oveq12d |  |-  ( k = 1 -> ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) ) | 
						
							| 92 | 91 | fsum1 |  |-  ( ( 1 e. ZZ /\ ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) e. CC ) -> sum_ k e. ( 1 ... 1 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) ) | 
						
							| 93 | 82 11 92 | sylancr |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> sum_ k e. ( 1 ... 1 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) ) | 
						
							| 94 |  | 1nn |  |-  1 e. NN | 
						
							| 95 | 93 94 | jctil |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 1 e. NN /\ sum_ k e. ( 1 ... 1 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 96 |  | eqidd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 97 | 47 73 81 63 95 96 | fsump1i |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 2 e. NN /\ sum_ k e. ( 1 ... 2 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) ) ) | 
						
							| 98 |  | eqidd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 99 | 47 64 72 63 97 98 | fsump1i |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 3 e. NN /\ sum_ k e. ( 1 ... 3 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) ) | 
						
							| 100 |  | eqidd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) ) = ( ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 101 | 47 48 56 63 99 100 | fsump1i |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( 4 e. NN /\ sum_ k e. ( 1 ... 4 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) ) ) ) | 
						
							| 102 | 101 | simprd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> sum_ k e. ( 1 ... 4 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( ( ( ( _i x. ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) ) + ( -u 1 x. ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) + ( -u _i x. ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( 1 x. ( ( N ` ( A G ( 1 S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 103 | 43 14 | subcld |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 104 | 9 18 | subcld |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) e. CC ) | 
						
							| 105 |  | mulcl |  |-  ( ( _i e. CC /\ ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) e. CC ) -> ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) e. CC ) | 
						
							| 106 | 7 104 105 | sylancr |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) e. CC ) | 
						
							| 107 | 103 106 | addcomd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) = ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 108 | 106 14 43 | subadd23d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( ( N ` ( A G B ) ) ^ 2 ) ) = ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) + ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) ) ) | 
						
							| 109 | 107 108 | eqtr4d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) = ( ( ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( ( N ` ( A G B ) ) ^ 2 ) ) ) | 
						
							| 110 | 46 102 109 | 3eqtr4d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> sum_ k e. ( 1 ... 4 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) = ( ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) ) | 
						
							| 111 | 110 | oveq1d |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( sum_ k e. ( 1 ... 4 ) ( ( _i ^ k ) x. ( ( N ` ( A G ( ( _i ^ k ) S B ) ) ) ^ 2 ) ) / 4 ) = ( ( ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) / 4 ) ) | 
						
							| 112 | 6 111 | eqtrd |  |-  ( ( U e. NrmCVec /\ A e. X /\ B e. X ) -> ( A P B ) = ( ( ( ( ( N ` ( A G B ) ) ^ 2 ) - ( ( N ` ( A G ( -u 1 S B ) ) ) ^ 2 ) ) + ( _i x. ( ( ( N ` ( A G ( _i S B ) ) ) ^ 2 ) - ( ( N ` ( A G ( -u _i S B ) ) ) ^ 2 ) ) ) ) / 4 ) ) |