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, if x were rich, then x is making tea. For all x, x is a bartender if and only if x will make tea. For all x, if x were a bartender, then x is making tea. There is at least one x for which x is not a bartender.
For all x, if x were a bartender, then x is making tea can be inferred via the universal biconditional elimination rule. For all x, if x makes tea, then x is a bartender can be inferred via the universal biconditional elimination rule. There is at least one x for which x will not make tea can be inferred via the existential biconditional elimination rule.