for m, n being Nat
for K being Field
for M, M1 being Matrix of m,n,K st M is without_repeated_line & ( for i being Nat st i in Seg m holds
ex a being Element of K st Line (M1,i) = a * (Line (M,i)) ) holds
ex L being Linear_Combination of lines M st L (#) (MX2FinS M) = M1