:: Hermitan Functionals. {C}anonical Construction of Scalar Product in Quotient Vector Space
:: by Jaros{\l}aw Kotowicz
::
:: Copyright (c) 2002-2021 Association of Mizar Users

Lm1: 0 = 0 + ()
;

theorem Th1: :: HERMITAN:1
for a being Complex st a = a *' holds
Im a = 0
proof end;

theorem Th2: :: HERMITAN:2
for a being Complex st a <> 0c holds
( |.(((Re a) / |.a.|) + (((- (Im a)) / |.a.|) * <i>)).| = 1 & Re ((((Re a) / |.a.|) + (((- (Im a)) / |.a.|) * <i>)) * a) = |.a.| & Im ((((Re a) / |.a.|) + (((- (Im a)) / |.a.|) * <i>)) * a) = 0 )
proof end;

theorem :: HERMITAN:3
for a being Complex ex b being Complex st
( |.b.| = 1 & Re (b * a) = |.a.| & Im (b * a) = 0 )
proof end;

theorem Th4: :: HERMITAN:4
for a being Element of COMPLEX holds a * (a *') = () + ()
proof end;

theorem :: HERMITAN:5
for a being Element of F_Complex st a = a *' holds
Im a = 0 by Th1;

theorem :: HERMITAN:6

theorem Th7: :: HERMITAN:7
for a being Element of F_Complex st a <> 0. F_Complex holds
( |.[**((Re a) / |.a.|),((- (Im a)) / |.a.|)**].| = 1 & Re ([**((Re a) / |.a.|),((- (Im a)) / |.a.|)**] * a) = |.a.| & Im ([**((Re a) / |.a.|),((- (Im a)) / |.a.|)**] * a) = 0 ) by ;

theorem Th8: :: HERMITAN:8
for a being Element of F_Complex ex b being Element of F_Complex st
( |.b.| = 1 & Re (b * a) = |.a.| & Im (b * a) = 0 )
proof end;

theorem Th9: :: HERMITAN:9
for a, b being Element of F_Complex holds
( Re (a - b) = (Re a) - (Re b) & Im (a - b) = (Im a) - (Im b) )
proof end;

theorem Th10: :: HERMITAN:10
for a, b being Element of F_Complex st Im a = 0 holds
( Re (a * b) = (Re a) * (Re b) & Im (a * b) = (Re a) * (Im b) )
proof end;

theorem :: HERMITAN:11
for a, b being Element of F_Complex st Im a = 0 & Im b = 0 holds
Im (a * b) = 0
proof end;

theorem Th12: :: HERMITAN:12
for a being Element of F_Complex st Im a = 0 holds
a = a *'
proof end;

theorem Th13: :: HERMITAN:13
for a being Element of F_Complex holds a * (a *') = |.a.| ^2
proof end;

theorem Th14: :: HERMITAN:14
for a being Element of F_Complex st 0 <= Re a & Im a = 0 holds
|.a.| = Re a
proof end;

theorem Th15: :: HERMITAN:15
for a being Element of F_Complex holds (Re a) + (Re (a *')) = 2 * (Re a)
proof end;

definition
let V be non empty ModuleStr over F_Complex ;
let f be Functional of V;
attr f is cmplxhomogeneous means :Def1: :: HERMITAN:def 1
for v being Vector of V
for a being Scalar of holds f . (a * v) = (a *') * (f . v);
end;

:: deftheorem Def1 defines cmplxhomogeneous HERMITAN:def 1 :
for V being non empty ModuleStr over F_Complex
for f being Functional of V holds
( f is cmplxhomogeneous iff for v being Vector of V
for a being Scalar of holds f . (a * v) = (a *') * (f . v) );

registration
let V be non empty ModuleStr over F_Complex ;
coherence
proof end;
end;

registration
let V be non empty right_complementable add-associative right_zeroed vector-distributive scalar-distributive scalar-associative scalar-unital ModuleStr over F_Complex ;
cluster Function-like V30( the carrier of V, the carrier of F_Complex) cmplxhomogeneous -> 0-preserving for Element of bool [: the carrier of V, the carrier of F_Complex:];
coherence
for b1 being Functional of V st b1 is cmplxhomogeneous holds
b1 is 0-preserving
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster V1() V4( the carrier of V) V5( the carrier of F_Complex) Function-like V30( the carrier of V, the carrier of F_Complex) additive 0-preserving V190() cmplxhomogeneous for Element of bool [: the carrier of V, the carrier of F_Complex:];
existence
ex b1 being Functional of V st
( b1 is additive & b1 is cmplxhomogeneous & b1 is 0-preserving )
proof end;
end;

definition end;

registration
let V be non empty ModuleStr over F_Complex ;
let f, g be cmplxhomogeneous Functional of V;
coherence
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
let f be cmplxhomogeneous Functional of V;
coherence
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
let a be Scalar of ;
let f be cmplxhomogeneous Functional of V;
coherence
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
let f, g be cmplxhomogeneous Functional of V;
coherence ;
end;

definition
let V be non empty ModuleStr over F_Complex ;
let f be Functional of V;
:: original: *'
redefine func f *' -> Functional of V means :Def2: :: HERMITAN:def 2
for v being Vector of V holds it . v = (f . v) *' ;
coherence
f *' is Functional of V
proof end;
compatibility
for b1 being Functional of V holds
( b1 = f *' iff for v being Vector of V holds b1 . v = (f . v) *' )
proof end;
end;

:: deftheorem Def2 defines *' HERMITAN:def 2 :
for V being non empty ModuleStr over F_Complex
for f, b3 being Functional of V holds
( b3 = f *' iff for v being Vector of V holds b3 . v = (f . v) *' );

registration
let A be non empty addMagma ;
let f be additive Function of A,F_Complex;
cluster f *' -> additive for Function of A,F_Complex;
coherence
for b1 being Function of A,F_Complex st b1 = f *' holds
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
let f be homogeneous Functional of V;
cluster f *' -> cmplxhomogeneous for Functional of V;
coherence
for b1 being Functional of V st b1 = f *' holds
b1 is cmplxhomogeneous
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
let f be cmplxhomogeneous Functional of V;
cluster f *' -> homogeneous for Functional of V;
coherence
for b1 being Functional of V st b1 = f *' holds
b1 is homogeneous
proof end;
end;

registration
let V be non trivial VectSp of F_Complex ;
let f be non constant Functional of V;
cluster f *' -> non constant ;
coherence
not f *' is constant
proof end;
end;

registration
let V be non trivial VectSp of F_Complex ;
cluster V1() V4( the carrier of V) V5( the carrier of F_Complex) non trivial Function-like non constant V30( the carrier of V, the carrier of F_Complex) additive V190() cmplxhomogeneous for Element of bool [: the carrier of V, the carrier of F_Complex:];
existence
ex b1 being Functional of V st
( b1 is additive & b1 is cmplxhomogeneous & not b1 is constant & not b1 is trivial )
proof end;
end;

theorem :: HERMITAN:16
for V being non empty ModuleStr over F_Complex
for f being Functional of V holds (f *') *' = f ;

theorem :: HERMITAN:17
for V being non empty ModuleStr over F_Complex holds () *' = 0Functional V
proof end;

theorem Th18: :: HERMITAN:18
for V being non empty ModuleStr over F_Complex
for f, g being Functional of V holds (f + g) *' = (f *') + (g *')
proof end;

theorem Th19: :: HERMITAN:19
for V being non empty ModuleStr over F_Complex
for f being Functional of V holds (- f) *' = - (f *')
proof end;

theorem :: HERMITAN:20
for V being non empty ModuleStr over F_Complex
for f being Functional of V
for a being Scalar of holds (a * f) *' = (a *') * (f *')
proof end;

theorem :: HERMITAN:21
for V being non empty ModuleStr over F_Complex
for f, g being Functional of V holds (f - g) *' = (f *') - (g *')
proof end;

theorem Th22: :: HERMITAN:22
for V being non empty ModuleStr over F_Complex
for f being Functional of V
for v being Vector of V holds
( f . v = 0. F_Complex iff (f *') . v = 0. F_Complex )
proof end;

theorem Th23: :: HERMITAN:23
for V being non empty ModuleStr over F_Complex
for f being Functional of V holds ker f = ker (f *')
proof end;

theorem :: HERMITAN:24
proof end;

theorem Th25: :: HERMITAN:25
for V being VectSp of F_Complex
for W being Subspace of V
for f being antilinear-Functional of V st the carrier of W c= ker (f *') holds
QFunctional (f,W) is cmplxhomogeneous
proof end;

definition
let V be VectSp of F_Complex ;
let f be antilinear-Functional of V;
func QcFunctional f -> antilinear-Functional of (VectQuot (V,(Ker (f *')))) equals :: HERMITAN:def 3
QFunctional (f,(Ker (f *')));
correctness
coherence
QFunctional (f,(Ker (f *'))) is antilinear-Functional of (VectQuot (V,(Ker (f *'))))
;
proof end;
end;

:: deftheorem defines QcFunctional HERMITAN:def 3 :
for V being VectSp of F_Complex
for f being antilinear-Functional of V holds QcFunctional f = QFunctional (f,(Ker (f *')));

theorem Th26: :: HERMITAN:26
for V being VectSp of F_Complex
for f being antilinear-Functional of V
for A being Vector of (VectQuot (V,(Ker (f *'))))
for v being Vector of V st A = v + (Ker (f *')) holds
() . A = f . v
proof end;

registration
let V be non trivial VectSp of F_Complex ;
let f be V23() antilinear-Functional of V;
cluster QcFunctional f -> V23() ;
coherence
not QcFunctional f is constant
proof end;
end;

registration
let V be VectSp of F_Complex ;
let f be antilinear-Functional of V;
coherence
not QcFunctional f is degenerated
proof end;
end;

::Sesquilinear Forms in Complex Vector Spaces
definition
let V, W be non empty ModuleStr over F_Complex ;
let f be Form of V,W;
attr f is cmplxhomogeneousFAF means :Def4: :: HERMITAN:def 4
for v being Vector of V holds FunctionalFAF (f,v) is cmplxhomogeneous ;
end;

:: deftheorem Def4 defines cmplxhomogeneousFAF HERMITAN:def 4 :
for V, W being non empty ModuleStr over F_Complex
for f being Form of V,W holds
( f is cmplxhomogeneousFAF iff for v being Vector of V holds FunctionalFAF (f,v) is cmplxhomogeneous );

theorem Th27: :: HERMITAN:27
for V, W being non empty ModuleStr over F_Complex
for v being Vector of V
for w being Vector of W
for a being Element of F_Complex
for f being Form of V,W st f is cmplxhomogeneousFAF holds
f . (v,(a * w)) = (a *') * (f . (v,w))
proof end;

definition
let V be non empty ModuleStr over F_Complex ;
let f be Form of V,V;
attr f is hermitan means :Def5: :: HERMITAN:def 5
for v, u being Vector of V holds f . (v,u) = (f . (u,v)) *' ;
attr f is diagRvalued means :Def6: :: HERMITAN:def 6
for v being Vector of V holds Im (f . (v,v)) = 0 ;
attr f is diagReR+0valued means :Def7: :: HERMITAN:def 7
for v being Vector of V holds 0 <= Re (f . (v,v));
end;

:: deftheorem Def5 defines hermitan HERMITAN:def 5 :
for V being non empty ModuleStr over F_Complex
for f being Form of V,V holds
( f is hermitan iff for v, u being Vector of V holds f . (v,u) = (f . (u,v)) *' );

:: deftheorem Def6 defines diagRvalued HERMITAN:def 6 :
for V being non empty ModuleStr over F_Complex
for f being Form of V,V holds
( f is diagRvalued iff for v being Vector of V holds Im (f . (v,v)) = 0 );

:: deftheorem Def7 defines diagReR+0valued HERMITAN:def 7 :
for V being non empty ModuleStr over F_Complex
for f being Form of V,V holds
( f is diagReR+0valued iff for v being Vector of V holds 0 <= Re (f . (v,v)) );

Lm2: now :: thesis: for V being non empty ModuleStr over F_Complex
for f being Functional of V
for v1, w being Vector of V holds (FormFunctional (f,())) . (v1,w) = 0. F_Complex
let V be non empty ModuleStr over F_Complex ; :: thesis: for f being Functional of V
for v1, w being Vector of V holds (FormFunctional (f,())) . (v1,w) = 0. F_Complex

let f be Functional of V; :: thesis: for v1, w being Vector of V holds (FormFunctional (f,())) . (v1,w) = 0. F_Complex
set 0F = 0Functional V;
let v1, w be Vector of V; :: thesis: (FormFunctional (f,())) . (v1,w) = 0. F_Complex
thus (FormFunctional (f,())) . (v1,w) = (f . v1) * (() . w) by BILINEAR:def 10
.= (f . v1) * () by HAHNBAN1:14
.= 0. F_Complex ; :: thesis: verum
end;

Lm3: for V being non empty ModuleStr over F_Complex
for f being Functional of V holds FormFunctional (f,()) is hermitan

proof end;

registration
let V, W be non empty ModuleStr over F_Complex ;
coherence
NulForm (V,W) is cmplxhomogeneousFAF
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster NulForm (V,V) -> hermitan ;
coherence
NulForm (V,V) is hermitan
proof end;
cluster NulForm (V,V) -> diagReR+0valued ;
coherence
NulForm (V,V) is diagReR+0valued
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) hermitan -> diagRvalued for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is hermitan holds
b1 is diagRvalued
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster V1() V4([: the carrier of V, the carrier of V:]) V5( the carrier of F_Complex) Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) additiveFAF additiveSAF homogeneousSAF V190() cmplxhomogeneousFAF hermitan diagRvalued diagReR+0valued for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
existence
ex b1 being Form of V,V st
( b1 is diagReR+0valued & b1 is hermitan & b1 is diagRvalued & b1 is additiveSAF & b1 is homogeneousSAF & b1 is additiveFAF & b1 is cmplxhomogeneousFAF )
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
cluster V1() V4([: the carrier of V, the carrier of W:]) V5( the carrier of F_Complex) Function-like V30([: the carrier of V, the carrier of W:], the carrier of F_Complex) additiveFAF additiveSAF homogeneousSAF V190() cmplxhomogeneousFAF for Element of bool [:[: the carrier of V, the carrier of W:], the carrier of F_Complex:];
existence
ex b1 being Form of V,W st
( b1 is additiveSAF & b1 is homogeneousSAF & b1 is additiveFAF & b1 is cmplxhomogeneousFAF )
proof end;
end;

definition end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) additiveFAF hermitan -> additiveSAF for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is hermitan & b1 is additiveFAF holds
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) additiveSAF hermitan -> additiveFAF for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is hermitan & b1 is additiveSAF holds
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) homogeneousSAF hermitan -> cmplxhomogeneousFAF for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is hermitan & b1 is homogeneousSAF holds
b1 is cmplxhomogeneousFAF
proof end;
end;

registration
let V be non empty ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) cmplxhomogeneousFAF hermitan -> homogeneousSAF for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is hermitan & b1 is cmplxhomogeneousFAF holds
b1 is homogeneousSAF
proof end;
end;

definition
let V be non empty ModuleStr over F_Complex ;
mode hermitan-Form of V is additiveSAF homogeneousSAF hermitan Form of V,V;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be Functional of V;
let g be cmplxhomogeneous Functional of W;
coherence
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be cmplxhomogeneousFAF Form of V,W;
let v be Vector of V;
coherence
FunctionalFAF (f,v) is cmplxhomogeneous
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f, g be cmplxhomogeneousFAF Form of V,W;
correctness
coherence ;
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be cmplxhomogeneousFAF Form of V,W;
let a be Scalar of ;
coherence
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be cmplxhomogeneousFAF Form of V,W;
coherence ;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f, g be cmplxhomogeneousFAF Form of V,W;
coherence ;
end;

registration
let V, W be non trivial VectSp of F_Complex ;
cluster V1() V4([: the carrier of V, the carrier of W:]) V5( the carrier of F_Complex) non trivial Function-like non constant V30([: the carrier of V, the carrier of W:], the carrier of F_Complex) additiveFAF additiveSAF homogeneousSAF V190() cmplxhomogeneousFAF for Element of bool [:[: the carrier of V, the carrier of W:], the carrier of F_Complex:];
existence
ex b1 being Form of V,W st
( b1 is additiveSAF & b1 is homogeneousSAF & b1 is additiveFAF & b1 is cmplxhomogeneousFAF & not b1 is constant & not b1 is trivial )
proof end;
end;

definition
let V, W be non empty ModuleStr over F_Complex ;
let f be Form of V,W;
func f *' -> Form of V,W means :Def8: :: HERMITAN:def 8
for v being Vector of V
for w being Vector of W holds it . (v,w) = (f . (v,w)) *' ;
existence
ex b1 being Form of V,W st
for v being Vector of V
for w being Vector of W holds b1 . (v,w) = (f . (v,w)) *'
proof end;
uniqueness
for b1, b2 being Form of V,W st ( for v being Vector of V
for w being Vector of W holds b1 . (v,w) = (f . (v,w)) *' ) & ( for v being Vector of V
for w being Vector of W holds b2 . (v,w) = (f . (v,w)) *' ) holds
b1 = b2
proof end;
end;

:: deftheorem Def8 defines *' HERMITAN:def 8 :
for V, W being non empty ModuleStr over F_Complex
for f, b4 being Form of V,W holds
( b4 = f *' iff for v being Vector of V
for w being Vector of W holds b4 . (v,w) = (f . (v,w)) *' );

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be additiveFAF Form of V,W;
coherence
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be additiveSAF Form of V,W;
coherence
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be homogeneousFAF Form of V,W;
coherence
proof end;
end;

registration
let V, W be non empty ModuleStr over F_Complex ;
let f be cmplxhomogeneousFAF Form of V,W;
coherence
proof end;
end;

registration
let V, W be non trivial VectSp of F_Complex ;
let f be non constant Form of V,W;
cluster f *' -> non constant ;
coherence
not f *' is constant
proof end;
end;

theorem Th28: :: HERMITAN:28
for V being non empty ModuleStr over F_Complex
for f being Functional of V
for v being Vector of V holds (FormFunctional (f,(f *'))) . (v,v) = |.(f . v).| ^2
proof end;

registration
let V be non empty ModuleStr over F_Complex ;
let f be Functional of V;
coherence
( FormFunctional (f,(f *')) is diagReR+0valued & FormFunctional (f,(f *')) is hermitan & FormFunctional (f,(f *')) is diagRvalued )
proof end;
end;

registration
let V be non trivial VectSp of F_Complex ;
cluster V1() V4([: the carrier of V, the carrier of V:]) V5( the carrier of F_Complex) non trivial Function-like non constant V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) additiveFAF additiveSAF homogeneousSAF V190() cmplxhomogeneousFAF hermitan diagRvalued diagReR+0valued for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
existence
ex b1 being Form of V,V st
( b1 is diagReR+0valued & b1 is hermitan & b1 is diagRvalued & b1 is additiveSAF & b1 is homogeneousSAF & b1 is additiveFAF & b1 is cmplxhomogeneousFAF & not b1 is constant & not b1 is trivial )
proof end;
end;

theorem :: HERMITAN:29
for V, W being non empty ModuleStr over F_Complex
for f being Form of V,W holds (f *') *' = f
proof end;

theorem :: HERMITAN:30
for V, W being non empty ModuleStr over F_Complex holds (NulForm (V,W)) *' = NulForm (V,W)
proof end;

theorem Th31: :: HERMITAN:31
for V, W being non empty ModuleStr over F_Complex
for f, g being Form of V,W holds (f + g) *' = (f *') + (g *')
proof end;

theorem Th32: :: HERMITAN:32
for V, W being non empty ModuleStr over F_Complex
for f being Form of V,W holds (- f) *' = - (f *')
proof end;

theorem :: HERMITAN:33
for V, W being non empty ModuleStr over F_Complex
for f being Form of V,W
for a being Element of F_Complex holds (a * f) *' = (a *') * (f *')
proof end;

theorem :: HERMITAN:34
for V, W being non empty ModuleStr over F_Complex
for f, g being Form of V,W holds (f - g) *' = (f *') - (g *')
proof end;

theorem Th35: :: HERMITAN:35
for V, W being VectSp of F_Complex
for v being Vector of V
for w, t being Vector of W
for f being additiveFAF cmplxhomogeneousFAF Form of V,W holds f . (v,(w - t)) = (f . (v,w)) - (f . (v,t))
proof end;

theorem Th36: :: HERMITAN:36
for V, W being VectSp of F_Complex
for v, u being Vector of V
for w, t being Vector of W
for f being sesquilinear-Form of V,W holds f . ((v - u),(w - t)) = ((f . (v,w)) - (f . (v,t))) - ((f . (u,w)) - (f . (u,t)))
proof end;

theorem Th37: :: HERMITAN:37
for V, W being non empty right_complementable add-associative right_zeroed vector-distributive scalar-distributive scalar-associative scalar-unital ModuleStr over F_Complex
for v, u being Vector of V
for w, t being Vector of W
for a, b being Element of F_Complex
for f being sesquilinear-Form of V,W holds f . ((v + (a * u)),(w + (b * t))) = ((f . (v,w)) + ((b *') * (f . (v,t)))) + ((a * (f . (u,w))) + (a * ((b *') * (f . (u,t)))))
proof end;

theorem Th38: :: HERMITAN:38
for V, W being VectSp of F_Complex
for v, u being Vector of V
for w, t being Vector of W
for a, b being Element of F_Complex
for f being sesquilinear-Form of V,W holds f . ((v - (a * u)),(w - (b * t))) = ((f . (v,w)) - ((b *') * (f . (v,t)))) - ((a * (f . (u,w))) - (a * ((b *') * (f . (u,t)))))
proof end;

theorem Th39: :: HERMITAN:39
for V being non empty right_complementable add-associative right_zeroed vector-distributive scalar-distributive scalar-associative scalar-unital ModuleStr over F_Complex
for f being cmplxhomogeneousFAF Form of V,V
for v being Vector of V holds f . (v,(0. V)) = 0. F_Complex
proof end;

theorem :: HERMITAN:40
for V being VectSp of F_Complex
for v, w being Vector of V
for f being hermitan-Form of V holds (((f . (v,w)) + (f . (v,w))) + (f . (v,w))) + (f . (v,w)) = (((f . ((v + w),(v + w))) - (f . ((v - w),(v - w)))) + (i_FC * (f . ((v + ()),(v + ()))))) - (i_FC * (f . ((v - ()),(v - ()))))
proof end;

definition
let V be non empty ModuleStr over F_Complex ;
let f be Form of V,V;
let v be Vector of V;
func signnorm (f,v) -> Real equals :: HERMITAN:def 9
Re (f . (v,v));
coherence
Re (f . (v,v)) is Real
;
end;

:: deftheorem defines signnorm HERMITAN:def 9 :
for V being non empty ModuleStr over F_Complex
for f being Form of V,V
for v being Vector of V holds signnorm (f,v) = Re (f . (v,v));

theorem Th41: :: HERMITAN:41
for V being non empty right_complementable add-associative right_zeroed vector-distributive scalar-distributive scalar-associative scalar-unital ModuleStr over F_Complex
for f being diagRvalued diagReR+0valued Form of V,V
for v being Vector of V holds
( |.(f . (v,v)).| = Re (f . (v,v)) & signnorm (f,v) = |.(f . (v,v)).| )
proof end;

::
:: Lemmas for Schwarz inequality
::
theorem Th42: :: HERMITAN:42
for V being VectSp of F_Complex
for v, w being Vector of V
for f being sesquilinear-Form of V,V
for r being Real
for a being Element of F_Complex st |.a.| = 1 holds
f . ((v - (([**r,0**] * a) * w)),(v - (([**r,0**] * a) * w))) = (((f . (v,v)) - ([**r,0**] * (a * (f . (w,v))))) - ([**r,0**] * ((a *') * (f . (v,w))))) + ([**(r ^2),0**] * (f . (w,w)))
proof end;

theorem Th43: :: HERMITAN:43
for V being VectSp of F_Complex
for v, w being Vector of V
for f being diagReR+0valued hermitan-Form of V
for r being Real
for a being Element of F_Complex st |.a.| = 1 & Re (a * (f . (w,v))) = |.(f . (w,v)).| holds
( Re (f . ((v - (([**r,0**] * a) * w)),(v - (([**r,0**] * a) * w)))) = ((signnorm (f,v)) - ((2 * |.(f . (w,v)).|) * r)) + ((signnorm (f,w)) * (r ^2)) & 0 <= ((signnorm (f,v)) - ((2 * |.(f . (w,v)).|) * r)) + ((signnorm (f,w)) * (r ^2)) )
proof end;

theorem Th44: :: HERMITAN:44
for V being VectSp of F_Complex
for v, w being Vector of V
for f being diagReR+0valued hermitan-Form of V st signnorm (f,w) = 0 holds
|.(f . (w,v)).| = 0
proof end;

:: Cauchy-Schwarz inequality
theorem Th45: :: HERMITAN:45
for V being VectSp of F_Complex
for v, w being Vector of V
for f being diagReR+0valued hermitan-Form of V holds |.(f . (v,w)).| ^2 <= (signnorm (f,v)) * (signnorm (f,w))
proof end;

theorem Th46: :: HERMITAN:46
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V
for v, w being Vector of V holds |.(f . (v,w)).| ^2 <= |.(f . (v,v)).| * |.(f . (w,w)).|
proof end;

:: Minkowski inequality
theorem Th47: :: HERMITAN:47
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V
for v, w being Vector of V holds signnorm (f,(v + w)) <= ((sqrt (signnorm (f,v))) + (sqrt (signnorm (f,w)))) ^2
proof end;

theorem :: HERMITAN:48
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V
for v, w being Vector of V holds |.(f . ((v + w),(v + w))).| <= ((sqrt |.(f . (v,v)).|) + (sqrt |.(f . (w,w)).|)) ^2
proof end;

theorem Th49: :: HERMITAN:49
for V being VectSp of F_Complex
for f being hermitan-Form of V
for v, w being Element of V holds (signnorm (f,(v + w))) + (signnorm (f,(v - w))) = (2 * (signnorm (f,v))) + (2 * (signnorm (f,w)))
proof end;

theorem :: HERMITAN:50
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V
for v, w being Element of V holds |.(f . ((v + w),(v + w))).| + |.(f . ((v - w),(v - w))).| = (2 * |.(f . (v,v)).|) + (2 * |.(f . (w,w)).|)
proof end;

definition
let V be non empty ModuleStr over F_Complex ;
let f be Form of V,V;
func quasinorm f -> RFunctional of V means :Def10: :: HERMITAN:def 10
for v being Element of V holds it . v = sqrt (signnorm (f,v));
existence
ex b1 being RFunctional of V st
for v being Element of V holds b1 . v = sqrt (signnorm (f,v))
proof end;
uniqueness
for b1, b2 being RFunctional of V st ( for v being Element of V holds b1 . v = sqrt (signnorm (f,v)) ) & ( for v being Element of V holds b2 . v = sqrt (signnorm (f,v)) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def10 defines quasinorm HERMITAN:def 10 :
for V being non empty ModuleStr over F_Complex
for f being Form of V,V
for b3 being RFunctional of V holds
( b3 = quasinorm f iff for v being Element of V holds b3 . v = sqrt (signnorm (f,v)) );

registration
let V be VectSp of F_Complex ;
let f be diagReR+0valued hermitan-Form of V;
coherence
proof end;
end;

:: Kernel of Hermitan Forms and Hermitan Forms in Quotinet Vector Spaces
registration
let V be non empty right_complementable add-associative right_zeroed vector-distributive scalar-distributive scalar-associative scalar-unital ModuleStr over F_Complex ;
let f be cmplxhomogeneousFAF Form of V,V;
cluster diagker f -> non empty ;
coherence
not diagker f is empty
proof end;
end;

theorem :: HERMITAN:51
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds diagker f is linearly-closed
proof end;

theorem Th52: :: HERMITAN:52
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds diagker f = leftker f
proof end;

theorem Th53: :: HERMITAN:53
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds diagker f = rightker f
proof end;

theorem :: HERMITAN:54
for V being non empty ModuleStr over F_Complex
for f being Form of V,V holds diagker f = diagker (f *')
proof end;

theorem Th55: :: HERMITAN:55
for V, W being non empty ModuleStr over F_Complex
for f being Form of V,W holds
( leftker f = leftker (f *') & rightker f = rightker (f *') )
proof end;

theorem Th56: :: HERMITAN:56
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds LKer f = RKer (f *')
proof end;

theorem Th57: :: HERMITAN:57
for V being VectSp of F_Complex
for f being diagRvalued diagReR+0valued Form of V,V
for v being Vector of V st Re (f . (v,v)) = 0 holds
f . (v,v) = 0. F_Complex
proof end;

theorem Th58: :: HERMITAN:58
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V
for v being Vector of V st Re (f . (v,v)) = 0 & ( not f is degenerated-on-left or not f is degenerated-on-right ) holds
v = 0. V
proof end;

definition
let V be non empty ModuleStr over F_Complex ;
let W be VectSp of F_Complex ;
let f be additiveFAF cmplxhomogeneousFAF Form of V,W;
func RQ*Form f -> additiveFAF cmplxhomogeneousFAF Form of V,(VectQuot (W,(RKer (f *')))) equals :: HERMITAN:def 11
(RQForm (f *')) *' ;
correctness
coherence
(RQForm (f *')) *' is additiveFAF cmplxhomogeneousFAF Form of V,(VectQuot (W,(RKer (f *'))))
;
;
end;

:: deftheorem defines RQ*Form HERMITAN:def 11 :
for V being non empty ModuleStr over F_Complex
for W being VectSp of F_Complex
for f being additiveFAF cmplxhomogeneousFAF Form of V,W holds RQ*Form f = (RQForm (f *')) *' ;

theorem Th59: :: HERMITAN:59
for V being non empty ModuleStr over F_Complex
for W being VectSp of F_Complex
for f being additiveFAF cmplxhomogeneousFAF Form of V,W
for v being Vector of V
for w being Vector of W holds () . (v,(w + (RKer (f *')))) = f . (v,w)
proof end;

registration
let V, W be VectSp of F_Complex ;
let f be sesquilinear-Form of V,W;
coherence
proof end;
coherence
proof end;
end;

definition
let V, W be VectSp of F_Complex ;
let f be sesquilinear-Form of V,W;
func Q*Form f -> sesquilinear-Form of (VectQuot (V,(LKer f))),(VectQuot (W,(RKer (f *')))) means :Def12: :: HERMITAN:def 12
for A being Vector of (VectQuot (V,(LKer f)))
for B being Vector of (VectQuot (W,(RKer (f *'))))
for v being Vector of V
for w being Vector of W st A = v + (LKer f) & B = w + (RKer (f *')) holds
it . (A,B) = f . (v,w);
existence
ex b1 being sesquilinear-Form of (VectQuot (V,(LKer f))),(VectQuot (W,(RKer (f *')))) st
for A being Vector of (VectQuot (V,(LKer f)))
for B being Vector of (VectQuot (W,(RKer (f *'))))
for v being Vector of V
for w being Vector of W st A = v + (LKer f) & B = w + (RKer (f *')) holds
b1 . (A,B) = f . (v,w)
proof end;
uniqueness
for b1, b2 being sesquilinear-Form of (VectQuot (V,(LKer f))),(VectQuot (W,(RKer (f *')))) st ( for A being Vector of (VectQuot (V,(LKer f)))
for B being Vector of (VectQuot (W,(RKer (f *'))))
for v being Vector of V
for w being Vector of W st A = v + (LKer f) & B = w + (RKer (f *')) holds
b1 . (A,B) = f . (v,w) ) & ( for A being Vector of (VectQuot (V,(LKer f)))
for B being Vector of (VectQuot (W,(RKer (f *'))))
for v being Vector of V
for w being Vector of W st A = v + (LKer f) & B = w + (RKer (f *')) holds
b2 . (A,B) = f . (v,w) ) holds
b1 = b2
proof end;
end;

:: deftheorem Def12 defines Q*Form HERMITAN:def 12 :
for V, W being VectSp of F_Complex
for f being sesquilinear-Form of V,W
for b4 being sesquilinear-Form of (VectQuot (V,(LKer f))),(VectQuot (W,(RKer (f *')))) holds
( b4 = Q*Form f iff for A being Vector of (VectQuot (V,(LKer f)))
for B being Vector of (VectQuot (W,(RKer (f *'))))
for v being Vector of V
for w being Vector of W st A = v + (LKer f) & B = w + (RKer (f *')) holds
b4 . (A,B) = f . (v,w) );

registration
let V, W be non trivial VectSp of F_Complex ;
let f be non constant sesquilinear-Form of V,W;
cluster Q*Form f -> non constant ;
coherence
not Q*Form f is constant
proof end;
end;

registration
let V be non empty right_zeroed ModuleStr over F_Complex ;
let W be VectSp of F_Complex ;
let f be additiveFAF cmplxhomogeneousFAF Form of V,W;
coherence
proof end;
end;

theorem Th60: :: HERMITAN:60
for V being non empty ModuleStr over F_Complex
for W being VectSp of F_Complex
for f being additiveFAF cmplxhomogeneousFAF Form of V,W holds leftker f = leftker ()
proof end;

theorem Th61: :: HERMITAN:61
for V, W being VectSp of F_Complex
for f being sesquilinear-Form of V,W holds RKer (f *') = RKer (() *')
proof end;

theorem Th62: :: HERMITAN:62
for V, W being VectSp of F_Complex
for f being sesquilinear-Form of V,W holds LKer f = LKer ()
proof end;

theorem Th63: :: HERMITAN:63
for V, W being VectSp of F_Complex
for f being sesquilinear-Form of V,W holds
( Q*Form f = RQ*Form () & Q*Form f = LQForm () )
proof end;

theorem Th64: :: HERMITAN:64
for V, W being VectSp of F_Complex
for f being sesquilinear-Form of V,W holds
( leftker () = leftker (RQ*Form ()) & rightker () = rightker (RQ*Form ()) & leftker () = leftker (LQForm ()) & rightker () = rightker (LQForm ()) )
proof end;

registration
let V, W be VectSp of F_Complex ;
let f be sesquilinear-Form of V,W;
coherence
( not RQ*Form () is degenerated-on-left & not RQ*Form () is degenerated-on-right )
proof end;
coherence
( not LQForm () is degenerated-on-left & not LQForm () is degenerated-on-right )
proof end;
end;

registration
let V, W be VectSp of F_Complex ;
let f be sesquilinear-Form of V,W;
coherence
( not Q*Form f is degenerated-on-left & not Q*Form f is degenerated-on-right )
proof end;
end;

:: Scalar Product in Quotient Vector Space Generated by Nonnegative Hermitan Form
definition
let V be non empty ModuleStr over F_Complex ;
let f be Form of V,V;
attr f is positivediagvalued means :: HERMITAN:def 13
for v being Vector of V st v <> 0. V holds
0 < Re (f . (v,v));
end;

:: deftheorem defines positivediagvalued HERMITAN:def 13 :
for V being non empty ModuleStr over F_Complex
for f being Form of V,V holds
( f is positivediagvalued iff for v being Vector of V st v <> 0. V holds
0 < Re (f . (v,v)) );

registration
let V be non empty right_zeroed ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) additiveSAF positivediagvalued -> diagReR+0valued for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is positivediagvalued & b1 is additiveSAF holds
b1 is diagReR+0valued
proof end;
end;

registration
let V be non empty right_zeroed ModuleStr over F_Complex ;
cluster Function-like V30([: the carrier of V, the carrier of V:], the carrier of F_Complex) additiveFAF positivediagvalued -> diagReR+0valued for Element of bool [:[: the carrier of V, the carrier of V:], the carrier of F_Complex:];
coherence
for b1 being Form of V,V st b1 is positivediagvalued & b1 is additiveFAF holds
b1 is diagReR+0valued
proof end;
end;

definition
let V be VectSp of F_Complex ;
let f be diagReR+0valued hermitan-Form of V;
func ScalarForm f -> diagReR+0valued hermitan-Form of (VectQuot (V,(LKer f))) equals :: HERMITAN:def 14
Q*Form f;
coherence
Q*Form f is diagReR+0valued hermitan-Form of (VectQuot (V,(LKer f)))
proof end;
end;

:: deftheorem defines ScalarForm HERMITAN:def 14 :
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds ScalarForm f = Q*Form f;

theorem :: HERMITAN:65
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V
for A, B being Vector of (VectQuot (V,(LKer f)))
for v, w being Vector of V st A = v + (LKer f) & B = w + (LKer f) holds
() . (A,B) = f . (v,w)
proof end;

theorem Th66: :: HERMITAN:66
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds leftker () = leftker ()
proof end;

theorem :: HERMITAN:67
for V being VectSp of F_Complex
for f being diagReR+0valued hermitan-Form of V holds rightker () = rightker () by Th56;

::
:: The From in Quotient Space Generated by Non negative Hermitan Form is the Scalar Product
::
registration
let V be VectSp of F_Complex ;
let f be diagReR+0valued hermitan-Form of V;
coherence
( not ScalarForm f is degenerated-on-left & not ScalarForm f is degenerated-on-right & ScalarForm f is positivediagvalued )
proof end;
end;

registration
let V be non trivial VectSp of F_Complex ;
let f be non constant diagReR+0valued hermitan-Form of V;
coherence
not ScalarForm f is constant
;
end;