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 y, if y were a mechanic, then y is a janitor. For all y, if y were fast, then y is a mechanic. For all y, y is a janitor or y will play tennis. For all y, if y were a janitor, then y is fast. For all y, y is not fast.
For all y, y is not a janitor can be inferred via the universal modus tollens rule. For all y, if y were a mechanic, then y is fast can be inferred via the universal transitivity rule. For all y, if y were fast, then y is a janitor can be inferred via the universal transitivity rule. For all y, if y were a janitor, then y is a mechanic can be inferred via the universal transitivity rule.