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 <-> p_16. p_16 <-> q_1. p_16 -> q_1.
r -> p_16 can be inferred via the biconditional elimination rule. p_16 -> q_1 can be inferred via the biconditional elimination rule. p_16 -> r can be inferred via the biconditional elimination rule. q_1 -> p_16 can be inferred via the biconditional elimination rule.