Which expression is logically equivalent to neg(P21lorQ21)\\neg(P_{21} \\lor Q_{21})neg(P21lorQ21)?
negP21landnegQ21\\neg P_{21} \\land \\neg Q_{21}negP21landnegQ21
P21landQ21P_{21} \\land Q_{21}P21landQ21
negP21impliesQ21\\neg P_{21} \\implies Q_{21}negP21impliesQ21
negP21lornegQ21\\neg P_{21} \\lor \\neg Q_{21}negP21lornegQ21