let n be Nat; :: thesis: for U being Subspace of n -VectSp_over F_Real
for W being Subspace of TOP-REAL n
for LU being Linear_Combination of U
for LW being Linear_Combination of W st LU = LW holds
( Carrier LU = Carrier LW & Sum LU = Sum LW )

set V = n -VectSp_over F_Real;
set T = TOP-REAL n;
let U be Subspace of n -VectSp_over F_Real; :: thesis: for W being Subspace of TOP-REAL n
for LU being Linear_Combination of U
for LW being Linear_Combination of W st LU = LW holds
( Carrier LU = Carrier LW & Sum LU = Sum LW )

let W be Subspace of TOP-REAL n; :: thesis: for LU being Linear_Combination of U
for LW being Linear_Combination of W st LU = LW holds
( Carrier LU = Carrier LW & Sum LU = Sum LW )

let LU be Linear_Combination of U; :: thesis: for LW being Linear_Combination of W st LU = LW holds
( Carrier LU = Carrier LW & Sum LU = Sum LW )

let LW be Linear_Combination of W; :: thesis: ( LU = LW implies ( Carrier LU = Carrier LW & Sum LU = Sum LW ) )
assume A1: LU = LW ; :: thesis: ( Carrier LU = Carrier LW & Sum LU = Sum LW )
reconsider LW9 = LW as Function of the carrier of W,REAL ;
defpred S1[ object , object ] means ( ( $1 in W & $2 = LW . $1 ) or ( not $1 in W & $2 = In (0,REAL) ) );
A2: ( dom LU = [#] U & dom LW = [#] W ) by FUNCT_2:def 1;
A3: for x being object st x in the carrier of (TOP-REAL n) holds
ex y being object st
( y in REAL & S1[x,y] )
proof
let x be object ; :: thesis: ( x in the carrier of (TOP-REAL n) implies ex y being object st
( y in REAL & S1[x,y] ) )

assume x in the carrier of (TOP-REAL n) ; :: thesis: ex y being object st
( y in REAL & S1[x,y] )

then reconsider x = x as VECTOR of (TOP-REAL n) ;
per cases ( x in W or not x in W ) ;
suppose A4: x in W ; :: thesis: ex y being object st
( y in REAL & S1[x,y] )

then reconsider x = x as VECTOR of W ;
S1[x,LW . x] by A4;
hence ex y being object st
( y in REAL & S1[x,y] ) ; :: thesis: verum
end;
suppose not x in W ; :: thesis: ex y being object st
( y in REAL & S1[x,y] )

hence ex y being object st
( y in REAL & S1[x,y] ) ; :: thesis: verum
end;
end;
end;
consider L being Function of the carrier of (TOP-REAL n),REAL such that
A5: for x being object st x in the carrier of (TOP-REAL n) holds
S1[x,L . x] from FUNCT_2:sch 1(A3);
A6: the carrier of W c= the carrier of (TOP-REAL n) by RLSUB_1:def 2;
then reconsider C = Carrier LW as finite Subset of (TOP-REAL n) by XBOOLE_1:1;
A7: L is Element of Funcs ( the carrier of (TOP-REAL n),REAL) by FUNCT_2:8;
now :: thesis: for v being VECTOR of (TOP-REAL n) st not v in C holds
L . v = 0
let v be VECTOR of (TOP-REAL n); :: thesis: ( not v in C implies L . v = 0 )
assume not v in C ; :: thesis: L . v = 0
then ( ( S1[v,LW . v] & not v in C & v in the carrier of W ) or S1[v, 0 ] ) by STRUCT_0:def 5;
then ( ( S1[v,LW . v] & LW . v = 0 ) or S1[v, 0 ] ) by RLVECT_2:19;
hence L . v = 0 by A5; :: thesis: verum
end;
then reconsider L = L as Linear_Combination of TOP-REAL n by A7, RLVECT_2:def 3;
reconsider L9 = L | the carrier of W as Function of the carrier of W,REAL by A6, FUNCT_2:32;
now :: thesis: for x being object st x in the carrier of W holds
LW9 . x = L9 . x
let x be object ; :: thesis: ( x in the carrier of W implies LW9 . x = L9 . x )
assume A8: x in the carrier of W ; :: thesis: LW9 . x = L9 . x
then S1[x,L . x] by A6, A5;
hence LW9 . x = L9 . x by A8, FUNCT_1:49, STRUCT_0:def 5; :: thesis: verum
end;
then A9: LW = L9 by FUNCT_2:12;
reconsider K = L as Linear_Combination of n -VectSp_over F_Real by Th1;
now :: thesis: for x being object st x in Carrier L holds
x in the carrier of W
let x be object ; :: thesis: ( x in Carrier L implies x in the carrier of W )
assume that
A10: x in Carrier L and
A11: not x in the carrier of W ; :: thesis: contradiction
consider v being VECTOR of (TOP-REAL n) such that
A12: x = v and
A13: L . v <> 0 by A10, RLVECT_5:3;
S1[v, 0 ] by A11, A12, STRUCT_0:def 5;
hence contradiction by A5, A13; :: thesis: verum
end;
then A14: Carrier L c= the carrier of W ;
then A15: ( Carrier L = Carrier LW & Sum L = Sum LW ) by A9, RLVECT_5:10;
A16: Carrier L = Carrier K by Th2;
then Sum K = Sum LU by A1, A2, A14, A9, VECTSP_9:7;
hence ( Carrier LU = Carrier LW & Sum LU = Sum LW ) by A1, A2, A9, A15, A16, Th5, VECTSP_9:7; :: thesis: verum