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: w <-> w_4. p or p_1. p_1 -> w_4. p -> w.
w -> w_4 can be inferred via the biconditional elimination rule. w_4 -> w can be inferred via the biconditional elimination rule.