let n be Element of NAT ; :: thesis: for K being Field
for M1, M2 being Matrix of n,K st M1 is line_circulant & M2 is line_circulant holds
M1 - M2 is line_circulant
let K be Field; :: thesis: for M1, M2 being Matrix of n,K st M1 is line_circulant & M2 is line_circulant holds
M1 - M2 is line_circulant
let M1, M2 be Matrix of n,K; :: thesis: ( M1 is line_circulant & M2 is line_circulant implies M1 - M2 is line_circulant )
assume A1: ( M1 is line_circulant & M2 is line_circulant ) ; :: thesis: M1 - M2 is line_circulant
then - M2 is line_circulant by Th11;
hence M1 - M2 is line_circulant by A1, Th7; :: thesis: verum