Consider the following premises. p. forall x_17: Q_17(x_17) -> P_17(x_17). P_17(a_16) or t. forall x_17: P_17(x_17) -> Q_17(x_17). t -> Q_17(a_16). Can we infer p and Q_17(a_16) from them? If possible, name the inference rules being used at each step.
 From forall x_17: P_17(x_17) -> Q_17(x_17), forall x_17: Q_17(x_17) -> P_17(x_17) we can infer forall x_17: P_17(x_17) <-> Q_17(x_17) via universal biconditional introduction. From forall x_17: P_17(x_17) <-> Q_17(x_17) we can infer P_17(a_16) <-> Q_17(a_16) via universal instantiation. From P_17(a_16) <-> Q_17(a_16) we can infer P_17(a_16) -> Q_17(a_16) via biconditional elimination. From P_17(a_16) -> Q_17(a_16), t -> Q_17(a_16), P_17(a_16) or t we can infer Q_17(a_16) via disjunction elimination. Finally, from p, Q_17(a_16) we can infer p and Q_17(a_16) via conjunction. Therefore, the answer is yes.