let V be Z_Module; :: thesis: for W being Submodule of V
for L being Z_Linear_Combination of V st Carrier L c= the carrier of W holds
ex K being Z_Linear_Combination of W st
( Carrier K = Carrier L & Sum K = Sum L )
let W be Submodule of V; :: thesis: for L being Z_Linear_Combination of V st Carrier L c= the carrier of W holds
ex K being Z_Linear_Combination of W st
( Carrier K = Carrier L & Sum K = Sum L )
let L be Z_Linear_Combination of V; :: thesis: ( Carrier L c= the carrier of W implies ex K being Z_Linear_Combination of W st
( Carrier K = Carrier L & Sum K = Sum L ) )
assume A1: Carrier L c= the carrier of W ; :: thesis: ex K being Z_Linear_Combination of W st
( Carrier K = Carrier L & Sum K = Sum L )
then reconsider C = Carrier L as finite Subset of W ;
the carrier of W c= the carrier of V by ZMODUL01:def 9;
then reconsider K = L | the carrier of W as Function of the carrier of W,INT by FUNCT_2:32;
A2: K is Element of Funcs ( the carrier of W,INT) by FUNCT_2:8;
A3: dom K = the carrier of W by FUNCT_2:def 1;

now :: thesis: for w being VECTOR of W st not w in C holds
K . w = 0

let w be VECTOR of W; :: thesis: ( not w in C implies K . w = 0 )
A4: w is VECTOR of V by ZMODUL01:25;
assume not w in C ; :: thesis: K . w = 0
then L . w = 0 by A4;
hence K . w = 0 by A3, FUNCT_1:47; :: thesis: verum

end;

then reconsider K = K as Z_Linear_Combination of W by A2, ZMODUL02:def 18;
take K ; :: thesis: ( Carrier K = Carrier L & Sum K = Sum L )
thus ( Carrier K = Carrier L & Sum K = Sum L ) by A1, Th11; :: thesis: verum