:: Bessel's Inequality
:: by Hiroshi Yamazaki , Yasunari Shidama and Yatsuka Nakamura
::
:: Received January 30, 2003
:: Copyright (c) 2003-2018 Association of Mizar Users
:: (Stowarzyszenie Uzytkownikow Mizara, Bialystok, Poland).
:: This code can be distributed under the GNU General Public Licence
:: version 3.0 or later, or the Creative Commons Attribution-ShareAlike
:: License version 3.0 or later, subject to the binding interpretation
:: detailed in file COPYING.interpretation.
:: See COPYING.GPL and COPYING.CC-BY-SA for the full text of these
:: licenses, or see http://www.gnu.org/licenses/gpl.html and
:: http://creativecommons.org/licenses/by-sa/3.0/.
environ
vocabularies NUMBERS, BHSP_1, PRE_TOPC, SUBSET_1, FINSEQ_1, FUNCT_1, RELAT_1,
FUNCT_2, CARD_1, TARSKI, XBOOLE_0, BINOP_1, SETWISEO, FINSET_1, MEMBER_1,
FINSOP_1, ALGSTR_0, SUPINF_2, NAT_1, DECOMP_1, REAL_1, STRUCT_0, BINOP_2,
PROB_2, NORMSP_1, ARYTM_3, SQUARE_1, ARYTM_1, XXREAL_0, RVSUM_1,
RLVECT_1, ORDINAL4, BHSP_5;
notations TARSKI, SUBSET_1, XBOOLE_0, CARD_1, ORDINAL1, NUMBERS, XCMPLX_0,
XXREAL_0, STRUCT_0, ALGSTR_0, REAL_1, XREAL_0, FUNCT_2, FINSET_1, NAT_1,
RELAT_1, BINOP_2, PRE_TOPC, RLVECT_1, BHSP_1, SQUARE_1, BINOP_1,
SETWISEO, FUNCT_1, FINSEQ_1, FINSOP_1;
constructors BINOP_1, DOMAIN_1, SETWISEO, REAL_1, SQUARE_1, NAT_1, BINOP_2,
MEMBERED, FINSOP_1, BHSP_1, RELSET_1, INT_1;
registrations XBOOLE_0, FUNCT_1, ORDINAL1, RELSET_1, FUNCT_2, FINSET_1,
NUMBERS, BINOP_2, MEMBERED, STRUCT_0, CARD_1, XREAL_0, SQUARE_1, NAT_1,
INT_1;
requirements SUBSET, REAL, BOOLE, NUMERALS, ARITHM;
begin :: Sum of the result of operation with each element of a set
reserve X for RealUnitarySpace;
reserve x, y, y1, y2 for Point of X;
reserve xd for set;
reserve i, j, n for Nat;
theorem :: BHSP_5:1
for D being set, p1, p2 being FinSequence of D holds
p1 is one-to-one & p2 is one-to-one & rng p1 = rng p2 implies
dom p1 = dom p2 & ex P being Permutation of dom p1 st
p2 = p1*P & dom P = dom p1 & rng P = dom p1;
definition
let DX be non empty set;
let f be BinOp of DX such that
f is commutative associative and
f is having_a_unity;
let Y be finite Subset of DX;
func f ++ Y -> Element of DX means
:: BHSP_5:def 1
ex p being FinSequence of DX st p is one-to-one & rng p = Y & it = f "**" p;
end;
definition
let X;
let Y be finite Subset of X;
func setop_SUM(Y,X) -> set equals
:: BHSP_5:def 2
(the addF of X) ++ Y if Y <> {} otherwise 0.X;
end;
definition
let X, x;
let p be FinSequence;
let i be Nat;
func PO(i,p,x) -> set equals
:: BHSP_5:def 3
(the scalar of X).[x,p.i];
end;
definition
let DK, DX be non empty set;
let F be Function of DX, DK;
let p be FinSequence of DX;
func Func_Seq(F,p) -> FinSequence of DK equals
:: BHSP_5:def 4
F*p;
end;
definition
let DK, DX be non empty set;
let f be BinOp of DK such that
f is commutative associative and
f is having_a_unity;
let Y be finite Subset of DX;
let F be Function of DX,DK;
func setopfunc(Y,DX,DK,F,f) -> Element of DK means
:: BHSP_5:def 5
ex p being FinSequence of DX st p is one-to-one &
rng p = Y & it = f "**" Func_Seq(F,p);
end;
definition
let X, x;
let Y be finite Subset of X;
func setop_xPre_PROD(x,Y,X) -> Real means
:: BHSP_5:def 6
ex p being FinSequence of the carrier of X st p is one-to-one & rng p = Y
& ex q being FinSequence of REAL st dom(q) = dom(p) &
(for i st i in dom q holds q.i = PO(i,p,x)) & it = addreal "**" q;
end;
definition
let X, x;
let Y be finite Subset of X;
func setop_xPROD(x,Y,X) -> Real equals
:: BHSP_5:def 7
setop_xPre_PROD(x,Y,X) if Y <> {}
otherwise 0;
end;
begin :: Orthogonal Family & Orthonormal Family
definition
let X;
mode OrthogonalFamily of X -> Subset of X means
:: BHSP_5:def 8
for x, y st x in it & y in it & x <> y holds x.|.y = 0;
end;
theorem :: BHSP_5:2
{} is OrthogonalFamily of X;
registration
let X;
cluster finite for OrthogonalFamily of X;
end;
definition
let X;
mode OrthonormalFamily of X -> Subset of X means
:: BHSP_5:def 9
it is OrthogonalFamily of X & for x st x in it holds x.|.x = 1;
end;
theorem :: BHSP_5:3
{} is OrthonormalFamily of X;
registration
let X;
cluster finite for OrthonormalFamily of X;
end;
theorem :: BHSP_5:4
x = 0.X iff for y holds x.|.y = 0;
begin :: Bessel's inequality
:: parallelogram law
theorem :: BHSP_5:5
||.x+y.||^2 + ||.x-y.||^2 = 2*||.x.||^2 + 2*||.y.||^2;
:: The Pythagorean theorem
theorem :: BHSP_5:6
x, y are_orthogonal implies ||.x+y.||^2 = ||.x.||^2 + ||.y.||^2;
theorem :: BHSP_5:7
for p be FinSequence of the carrier of X st (len p >=1 &
for i,j st i in dom p & j in dom p & i <> j
holds (the scalar of X).[p.i,p.j]=0) for q be FinSequence of REAL
st dom p = dom q &
(for i st i in dom q holds q.i = (the scalar of X).[(p.i),(p.i)])
holds ((the addF of X) "**" p).|. ((the addF of X) "**" p) = addreal "**" q;
theorem :: BHSP_5:8
for p be FinSequence of the carrier of X st len p >= 1
for q be FinSequence of REAL st dom p = dom q &
(for i st i in dom q holds q.i = (the scalar of X).[x,p.i])
holds x.|.((the addF of X) "**" p) = addreal "**" q;
theorem :: BHSP_5:9
for S be finite non empty Subset of X
for F be Function of the carrier of X, the carrier of X
st S c= dom F & (for y1,y2 st y1 in S & y2 in S & y1 <> y2
holds (the scalar of X).[F.y1,F.y2] = 0)
for H be Function of the carrier of X, REAL
st S c= dom H & (for y st y in S holds H.y= (the scalar of X).[F.y,F.y])
for p be FinSequence of the carrier of X
st p is one-to-one & rng p = S holds
(the scalar of X).[(the addF of X) "**" Func_Seq(F,p),
(the addF of X) "**" Func_Seq(F,p)] = addreal "**" Func_Seq(H,p);
theorem :: BHSP_5:10
for S be finite non empty Subset of X
for F be Function of the carrier of X, the carrier of X st S c= dom F
for H be Function of the carrier of X, REAL
st S c= dom H & (for y st y in S holds H.y = (the scalar of X).[x,F.y])
for p be FinSequence of the carrier of X st p is one-to-one & rng p = S
holds (the scalar of X).[x,(the addF of X) "**" Func_Seq(F,p) ]
= addreal "**" Func_Seq(H,p);
theorem :: BHSP_5:11
for X st the addF of X is commutative associative &
the addF of X is having_a_unity for x
for S be finite OrthonormalFamily of X st S is non empty
for H be Function of the carrier of X, REAL st
S c= dom H & (for y st y in S holds H.y= (x.|.y)^2)
for F be Function of the carrier of X, the carrier of X st
S c= dom F & (for y st y in S holds F.y = (x.|.y)*y) holds
x.|.setopfunc(S, the carrier of X, the carrier of X, F, the addF of X)
= setopfunc(S, the carrier of X, REAL, H, addreal);
theorem :: BHSP_5:12
for X st the addF of X is commutative associative &
the addF of X is having_a_unity
for x for S be finite OrthonormalFamily of X st S is non empty
for F be Function of the carrier of X, the carrier of X
st S c= dom F & (for y st y in S holds F.y = (x.|.y)*y)
for H be Function of the carrier of X, REAL
st S c= dom H & (for y st y in S holds H.y= (x.|.y)^2) holds
setopfunc(S, the carrier of X, the carrier of X, F, the addF of X)
.|. setopfunc(S, the carrier of X, the carrier of X, F, the addF of X)
= setopfunc(S, the carrier of X, REAL, H, addreal);
theorem :: BHSP_5:13
for X st the addF of X is commutative associative &
the addF of X is having_a_unity for x
for S be finite OrthonormalFamily of X st S is non empty
for H be Function of the carrier of X, REAL
st S c= dom H & (for y st y in S holds H.y = (x.|.y)^2) holds
setopfunc(S, the carrier of X, REAL, H, addreal) <= ||.x.||^2;
theorem :: BHSP_5:14
for DK, DX be non empty set
for f be BinOp of DK st f is commutative associative & f is having_a_unity
for Y1, Y2 be finite Subset of DX st Y1 misses Y2
for F be Function of DX, DK st Y1 c= dom F & Y2 c= dom F
for Z be finite Subset of DX st Z = Y1 \/ Y2 holds setopfunc(Z,DX,DK,F,f)
= f.(setopfunc(Y1,DX,DK,F,f), setopfunc(Y2,DX,DK,F,f));