let n be 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
let K be 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
let a, b, c be 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
let M1, M2, M3 be Matrix of n,K; ( M1 is col_circulant & M2 is col_circulant & M3 is col_circulant implies ((a * M1) - (b * M2)) + (c * M3) is col_circulant )
assume
( M1 is col_circulant & M2 is col_circulant & M3 is col_circulant )
; ((a * M1) - (b * M2)) + (c * M3) is col_circulant
then
( c * M3 is col_circulant & (a * M1) - (b * M2) is col_circulant )
by Th20, Th27;
hence
((a * M1) - (b * M2)) + (c * M3) is col_circulant
by Th21; verum