Consider the following premises. forall x_19: P_19(x_19) and Q_19(x_19). forall x_19: P_11(x_19) <-> Q_6(x_19). exists x_19: P_11(x_19) -> ~P_19(x_19). forall x_19: U_3(x_19) -> Q_6(x_19). Can we infer forall x_19: P_11(x_19) <-> Q_6(x_19) from them? If possible, name the inference rules being used at each step.
That is one of the premises. Therefore, the answer is yes.