for n being Nat
for K being Field
for M being Matrix of K
for nt, nt1, nt9, nt19 being Element of n -tuples_on NAT st rng nt = rng nt9 & rng nt1 = rng nt19 & not Det (Segm (M,nt,nt1)) = Det (Segm (M,nt9,nt19)) holds
Det (Segm (M,nt,nt1)) = - (Det (Segm (M,nt9,nt19)))