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 or p. w_1 <-> w. ~w_1.
w_1 -> w can be inferred via the biconditional elimination rule. w -> w_1 can be inferred via the biconditional elimination rule. ~w can be inferred via the biconditional elimination rule.