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 -> q. ~p_12. p_15 -> t. p_12 <-> q. w -> p_15.
p_15 -> q can be inferred via the transitivity rule. p_12 -> q can be inferred via the biconditional elimination rule. q -> p_12 can be inferred via the biconditional elimination rule. ~q can be inferred via the biconditional elimination rule.