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_4. p_15 <-> t_4. p_15 or p_3. t_4 <-> p_15.
p_15 -> t_4 can be inferred via the biconditional elimination rule. t_4 -> p_15 can be inferred via the biconditional elimination rule. t_4 -> p_15 can be inferred via the biconditional elimination rule. p_15 -> t_4 can be inferred via the biconditional elimination rule. ~p_15 can be inferred via the biconditional elimination rule. ~p_15 can be inferred via the biconditional elimination rule.