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 sailor, then y is rich. For all y, y is a nurse or y is happy. For all y, if y were rich, then y is driving a car. For all y, if y were happy, then y is a sailor. For all y, if y were a nurse, then y is a sailor.
For all y, if y were a sailor, then y is driving a car can be inferred via the universal transitivity rule. For all y, if y were happy, then y is rich can be inferred via the universal transitivity rule. For all y, if y were a nurse, then y is rich can be inferred via the universal transitivity rule. For all y, y is a sailor can be inferred via the universal disjunction elimination rule.