let V be RealLinearSpace; for L1, L2 being Linear_Combination of V holds (vector (LC_RLSpace V),L1) - (vector (LC_RLSpace V),L2) = L1 - L2
let L1, L2 be Linear_Combination of V; (vector (LC_RLSpace V),L1) - (vector (LC_RLSpace V),L2) = L1 - L2
- L2 in LinComb V
by Def16;
then A1:
- L2 in LC_RLSpace V
by STRUCT_0:def 5;
- (vector (LC_RLSpace V),L2) =
- L2
by Th98
.=
vector (LC_RLSpace V),(- L2)
by A1, Def1
;
hence
(vector (LC_RLSpace V),L1) - (vector (LC_RLSpace V),L2) = L1 - L2
by Th96; verum