theorem :: MATRIX15:71
for m being Nat
for K being Field
for W being strict Subspace of m -VectSp_over K st dim W < m holds
ex A being Matrix of m -' (dim W),m,K ex N being finite without_zero Subset of NAT st
( card N = m -' (dim W) & N c= Seg m & Segm (A,(Seg (m -' (dim W))),N) = 1. (K,(m -' (dim W))) & W = Space_of_Solutions_of A )