FDL > PVS > Number Theory > gcd > gcd is max > pf:gcd is max > 1 > 1 > 2 > 1 > 1 > 1 > 1

Conclusion

-1. (i!1 /= 0) OR (j!1 /= 0)

1. (i!1 = 0) = > (j!1 /= 0)