theorem :: MATRIX16:30

for n being Element of NAT
for K being Field
for a, b, c being Element of K
for M1, M2, M3 being Matrix of n,K st M1 is col_circulant & M2 is col_circulant & M3 is col_circulant holds
((a * M1) - (b * M2)) + (c * M3) is col_circulant