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: t_1 <-> T_2(a). forall y: ~P(y). forall y: P(y) or ~T_2(y).
t_1 -> T_2(a) can be inferred via the biconditional elimination rule. T_2(a) -> t_1 can be inferred via the biconditional elimination rule. forall y: T_2(y) -> P(y) can be inferred via the universal rewriting rule.