The following configuration of gate is equivalent to

NAND gate XOR gate OR gate NOR gate

XOR gate

$Y'=\overline{A+B}$    $Y=\overline{\overline{A+B}}=A+B$ Truth table of the given circuit is given by  A   B   Y'   Y  0 0 1 0 0 1 0 1 1 0 0 1 1 1 0 1