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_5, if x_5 were a doctor, then x_5 is a sailor. For all x_5, if x_5 were a cashier, then x_5 is a doctor. For all x_5, if x_5 were a sailor, then x_5 is reading a book. For all x_5, if x_5 reads a book, then x_5 is poor.
For all x_5, if x_5 were a doctor, then x_5 is reading a book can be inferred via the universal transitivity rule. For all x_5, if x_5 were a cashier, then x_5 is a sailor can be inferred via the universal transitivity rule. For all x_5, if x_5 were a sailor, then x_5 is poor can be inferred via the universal transitivity rule.