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: p_6 -> w_4. w_4 -> p. w_1 -> p_6. w_1 <-> p.
p_6 -> p can be inferred via the transitivity rule. w_1 -> w_4 can be inferred via the transitivity rule. w_1 -> p can be inferred via the biconditional elimination rule. p -> w_1 can be inferred via the biconditional elimination rule.