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_9, x_9 will make tea if and only if x_9 is a sailor. If Sarah makes tea, then Sarah is a sailor.
For all x_9, if x_9 makes tea, then x_9 is a sailor can be inferred via the universal biconditional elimination rule. For all x_9, if x_9 were a sailor, then x_9 is making tea can be inferred via the universal biconditional elimination rule.