let G be Group; :: thesis: for N1, N2 being strict normal Subgroup of G holds the carrier of (N1 "\/" N2) = N1 * N2
let N1, N2 be strict normal Subgroup of G; :: thesis: the carrier of (N1 "\/" N2) = N1 * N2
N1 * N2 = N2 * N1 by GROUP_3:125;
hence the carrier of (N1 "\/" N2) = N1 * N2 by Th51; :: thesis: verum