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: r_3 -> q. p -> r_3. q -> r_3. p or q.
p -> q can be inferred via the transitivity rule. r_3 can be inferred via the disjunction elimination rule. r_3 <-> q can be inferred via the biconditional introduction rule. q <-> r_3 can be inferred via the biconditional introduction rule.