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: p_1 <-> s. p_1 or ~t_4.
t_4 -> p_1 can be inferred via the rewriting rule. p_1 -> s can be inferred via the biconditional elimination rule. s -> p_1 can be inferred via the biconditional elimination rule.