Consider the following premises. forall y_3: S_1(y_3). forall y_3: S_1(y_3) -> S_4(y_3). Can we infer forall y_3: S_4(y_3) from them? If possible, name the inference rules being used at each step.
We can infer forall y_3: S_4(y_3) via the universal modus ponens rule. Therefore, the answer is yes.