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 -> t. t <-> p. p -> w. p_6.
t can be inferred via the modus ponens rule. t -> p can be inferred via the biconditional elimination rule. p -> t can be inferred via the biconditional elimination rule.