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_6, if x_6 reads a book, then x_6 is cooking. For all x_6, if x_6 cooks, then x_6 is playing tennis. For all x_6, if x_6 works, then x_6 is reading a book. There is at least one x_6 for which if x_6 plays tennis, then x_6 is a janitor.
For all x_6, if x_6 reads a book, then x_6 is playing tennis can be inferred via the universal transitivity rule. For all x_6, if x_6 works, then x_6 is cooking can be inferred via the universal transitivity rule. There is at least one x_6 for which if x_6 cooks, then x_6 is a janitor can be inferred via the existential transitivity rule.