let GF be non empty right_complementable well-unital distributive Abelian add-associative right_zeroed associative doubleLoopStr ; for V being non empty right_complementable vector-distributive scalar-distributive scalar-associative scalar-unital Abelian add-associative right_zeroed ModuleStr over GF
for V1 being Subset of V st V1 <> {} & V1 is linearly-closed holds
ex W being strict Subspace of V st V1 = the carrier of W
let V be non empty right_complementable vector-distributive scalar-distributive scalar-associative scalar-unital Abelian add-associative right_zeroed ModuleStr over GF; for V1 being Subset of V st V1 <> {} & V1 is linearly-closed holds
ex W being strict Subspace of V st V1 = the carrier of W
let V1 be Subset of V; ( V1 <> {} & V1 is linearly-closed implies ex W being strict Subspace of V st V1 = the carrier of W )
assume that
A1:
V1 <> {}
and
A2:
V1 is linearly-closed
; ex W being strict Subspace of V st V1 = the carrier of W
reconsider D = V1 as non empty set by A1;
reconsider d = 0. V as Element of D by A2, Th1;
set VV = the carrier of V;
set C = (comp V) | D;
dom (comp V) = the carrier of V
by FUNCT_2:def 1;
then A3:
dom ((comp V) | D) = D
by RELAT_1:62;
A4:
rng ((comp V) | D) c= D
set M = the lmult of V | [: the carrier of GF,D:];
dom the lmult of V = [: the carrier of GF, the carrier of V:]
by FUNCT_2:def 1;
then A7:
dom ( the lmult of V | [: the carrier of GF,D:]) = [: the carrier of GF,D:]
by RELAT_1:62, ZFMISC_1:96;
A8:
rng ( the lmult of V | [: the carrier of GF,D:]) c= D
proof
let x be
object ;
TARSKI:def 3 ( not x in rng ( the lmult of V | [: the carrier of GF,D:]) or x in D )
assume
x in rng ( the lmult of V | [: the carrier of GF,D:])
;
x in D
then consider y being
object such that A9:
y in dom ( the lmult of V | [: the carrier of GF,D:])
and A10:
( the lmult of V | [: the carrier of GF,D:]) . y = x
by FUNCT_1:def 3;
consider y1,
y2 being
object such that A11:
[y1,y2] = y
by A7, A9, RELAT_1:def 1;
reconsider y1 =
y1 as
Element of
GF by A7, A9, A11, ZFMISC_1:87;
A12:
y2 in V1
by A7, A9, A11, ZFMISC_1:87;
then reconsider y2 =
y2 as
Element of
V ;
x = y1 * y2
by A9, A10, A11, FUNCT_1:47;
hence
x in D
by A2, A12;
verum
end;
set A = the addF of V || D;
dom the addF of V = [: the carrier of V, the carrier of V:]
by FUNCT_2:def 1;
then A13:
dom ( the addF of V || D) = [:D,D:]
by RELAT_1:62, ZFMISC_1:96;
A14:
rng ( the addF of V || D) c= D
proof
let x be
object ;
TARSKI:def 3 ( not x in rng ( the addF of V || D) or x in D )
assume
x in rng ( the addF of V || D)
;
x in D
then consider y being
object such that A15:
y in dom ( the addF of V || D)
and A16:
( the addF of V || D) . y = x
by FUNCT_1:def 3;
consider y1,
y2 being
object such that A17:
[y1,y2] = y
by A13, A15, RELAT_1:def 1;
A18:
(
y1 in D &
y2 in D )
by A13, A15, A17, ZFMISC_1:87;
then reconsider y1 =
y1,
y2 =
y2 as
Element of
V ;
x = y1 + y2
by A15, A16, A17, FUNCT_1:47;
hence
x in D
by A2, A18;
verum
end;
reconsider M = the lmult of V | [: the carrier of GF,D:] as Function of [: the carrier of GF,D:],D by A7, A8, FUNCT_2:def 1, RELSET_1:4;
reconsider C = (comp V) | D as UnOp of D by A3, A4, FUNCT_2:def 1, RELSET_1:4;
reconsider A = the addF of V || D as BinOp of D by A13, A14, FUNCT_2:def 1, RELSET_1:4;
set W = ModuleStr(# D,A,d,M #);
A19:
for a, b being Element of ModuleStr(# D,A,d,M #)
for x, y being Element of V st x = a & b = y holds
a + b = x + y
A21:
( ModuleStr(# D,A,d,M #) is Abelian & ModuleStr(# D,A,d,M #) is add-associative & ModuleStr(# D,A,d,M #) is right_zeroed & ModuleStr(# D,A,d,M #) is right_complementable )
proof
thus
ModuleStr(#
D,
A,
d,
M #) is
Abelian
( ModuleStr(# D,A,d,M #) is add-associative & ModuleStr(# D,A,d,M #) is right_zeroed & ModuleStr(# D,A,d,M #) is right_complementable )
let a be
Element of
ModuleStr(#
D,
A,
d,
M #);
ALGSTR_0:def 16 a is right_complementable
reconsider x =
a as
Element of
V by TARSKI:def 3;
reconsider a9 =
a as
Element of
D ;
reconsider b =
C . a9 as
Element of
D ;
reconsider b =
b as
Element of
ModuleStr(#
D,
A,
d,
M #) ;
take
b
;
ALGSTR_0:def 11 a + b = 0. ModuleStr(# D,A,d,M #)
thus a + b =
x + ((comp V) . x)
by A3, A19, FUNCT_1:47
.=
x + (- x)
by VECTSP_1:def 13
.=
0. ModuleStr(#
D,
A,
d,
M #)
by RLVECT_1:5
;
verum
end;
A23:
ModuleStr(# D,A,d,M #) is vector-distributive
proof
let a be
Element of
GF;
VECTSP_1:def 13 for b1, b2 being Element of the carrier of ModuleStr(# D,A,d,M #) holds a * (b1 + b2) = (a * b1) + (a * b2)let v,
w be
Element of
ModuleStr(#
D,
A,
d,
M #);
a * (v + w) = (a * v) + (a * w)
reconsider x =
v,
y =
w as
Element of
V by TARSKI:def 3;
then A26:
a * v = a * x
;
A27:
a * w = a * y
by A24;
v + w = x + y
by A19;
hence a * (v + w) =
a * (x + y)
by A24
.=
(a * x) + (a * y)
by VECTSP_1:def 14
.=
(a * v) + (a * w)
by A19, A26, A27
;
verum
end;
A28:
ModuleStr(# D,A,d,M #) is scalar-distributive
A33:
ModuleStr(# D,A,d,M #) is scalar-associative
ModuleStr(# D,A,d,M #) is scalar-unital
then reconsider W = ModuleStr(# D,A,d,M #) as non empty right_complementable vector-distributive scalar-distributive scalar-associative scalar-unital Abelian add-associative right_zeroed ModuleStr over GF by A21, A23, A28, A33;
0. W = 0. V
;
then reconsider W = W as strict Subspace of V by Def2;
take
W
; V1 = the carrier of W
thus
V1 = the carrier of W
; verum