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: forall y: P(y) -> U_2(y). P(d) or q_7. forall y: U_2(y) -> P(y). U_2(d) or ~q_7.
q_7 -> U_2(d) can be inferred via the rewriting rule. forall y: P(y) <-> U_2(y) can be inferred via the universal biconditional introduction rule. forall y: U_2(y) <-> P(y) can be inferred via the universal biconditional introduction rule.