Consider the following premises. ~Q_10(g). forall x_10: P_10(x_10) <-> Q_10(x_10). Q_10(g) -> P_10(g). Can we infer P_10(g) from them? If possible, name the inference rules being used at each step.
 From forall x_10: P_10(x_10) <-> Q_10(x_10) we can infer forall x_10: P_10(x_10) -> Q_10(x_10) via universal biconditional elimination. From forall x_10: P_10(x_10) -> Q_10(x_10) we can infer P_10(g) -> Q_10(g) via universal instantiation. From P_10(g) -> Q_10(g), Q_10(g) -> P_10(g) we can infer P_10(g) <-> Q_10(g) via biconditional introduction. Finally, from P_10(g) <-> Q_10(g), ~Q_10(g) we can infer ~P_10(g) via biconditional elimination, which contradicts P_10(g). Therefore, the answer is no.