for n being Nat
for K being Field
for A, B being Matrix of K
for nt being Element of n -tuples_on NAT st rng nt c= dom A & n > 0 holds
Solutions_of (A,B) c= Solutions_of ((Segm (A,nt,(Sgm (Seg (width A))))),(Segm (B,nt,(Sgm (Seg (width B))))))