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 <-> P(c_4). s_2 -> t. forall y_1: ~P(y_1).
t -> P(c_4) can be inferred via the biconditional elimination rule. P(c_4) -> t can be inferred via the biconditional elimination rule.