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: Q(i) <-> Q_1(i). forall y: Q_1(y) <-> Q(y).
Q(i) -> Q_1(i) can be inferred via the biconditional elimination rule. Q_1(i) -> Q(i) can be inferred via the biconditional elimination rule. forall y: Q_1(y) -> Q(y) can be inferred via the universal biconditional elimination rule. forall y: Q(y) -> Q_1(y) can be inferred via the universal biconditional elimination rule.