let V be non empty CLSStruct ; :: thesis: for L being C_Linear_Combination of V holds - (- L) = L
let L be C_Linear_Combination of V; :: thesis: - (- L) = L
let v be VECTOR of V; :: according to CONVEX4:def 7 :: thesis: (- (- L)) . v = L . v
thus (- (- L)) . v = (((- 1r) * (- 1r)) * L) . v by Th29
.= 1r * (L . v) by Def9
.= L . v ; :: thesis: verum