theorem Th8:
  Z_Lin(A) c= the carrier of Lin(A)
proof
    let x be object;
    assume x in Z_Lin(A); then
    consider l1 being Linear_Combination of A such that
A1: x = Sum(l1) & rng l1 c= INT;
    x in Lin(A) by A1,RLVECT_3:14;
    hence thesis by STRUCT_0:def 5;
end;
