Two NOR gates are connected in series with each other. They result in the logic operation as

A B x1 x2 x3 y 0 0 0 1 1 0 1 0 1 0 0 1 0 1 1 0 0 1 1 1 1 0 0 1 Bx1 x2 x3 y 000110101001011001111001Two NOR gates in series are equivalent to an OR gate