What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: exists x_1: U(x_1) -> U_1(x_1). forall x_1: U_1(x_1) <-> Q(x_1). forall x_1: U(x_1).
exists x_1: U_1(x_1) can be inferred via the existential modus ponens rule. forall x_1: U_1(x_1) -> Q(x_1) can be inferred via the universal biconditional elimination rule. forall x_1: Q(x_1) -> U_1(x_1) can be inferred via the universal biconditional elimination rule.