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_3. w or q. t. q -> r. p_31 <-> r. w -> r.
q_3 can be inferred via the modus ponens rule. r can be inferred via the disjunction elimination rule. p_31 -> r can be inferred via the biconditional elimination rule. r -> p_31 can be inferred via the biconditional elimination rule.