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_14, if x_14 were rich, then x_14 is a mechanic. For all x_14, if x_14 were a mechanic, then x_14 is rich. For all x_14, x_14 is rich if and only if x_14 is curious. There is at least one x_14 for which if x_14 were a mechanic, then x_14 is making tea.
There is at least one x_14 for which if x_14 were rich, then x_14 is making tea can be inferred via the existential transitivity rule. For all x_14, x_14 is rich if and only if x_14 is a mechanic can be inferred via the universal biconditional introduction rule. For all x_14, x_14 is a mechanic if and only if x_14 is rich can be inferred via the universal biconditional introduction rule. For all x_14, if x_14 were rich, then x_14 is curious can be inferred via the universal biconditional elimination rule. For all x_14, if x_14 were curious, then x_14 is rich can be inferred via the universal biconditional elimination rule.