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: For all x_16, x_16 is a writer or x_16 will take a plane. There is at least one x_16 for which x_16 will not take a plane. For all x_16, x_16 is not a writer or x_16 will cook. For all x_16, if x_16 cooks, then x_16 is an office clerk. For all x_16, if x_16 were an office clerk, then x_16 is cooking.
For all x_16, x_16 will take a plane or x_16 will cook can be inferred via the universal resolution rule. For all x_16, x_16 will cook if and only if x_16 is an office clerk can be inferred via the universal biconditional introduction rule. For all x_16, x_16 is an office clerk if and only if x_16 will cook can be inferred via the universal biconditional introduction rule.