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, y is not rich. For all y, y is a police officer if and only if y will take a plane. For all y, y will take a plane if and only if y is rich. For all y, y is a police officer if and only if y is a lawyer.
For all y, if y were a police officer, then y is taking a plane can be inferred via the universal biconditional elimination rule. For all y, if y takes a plane, then y is rich can be inferred via the universal biconditional elimination rule. For all y, if y were a police officer, then y is a lawyer can be inferred via the universal biconditional elimination rule. For all y, if y takes a plane, then y is a police officer can be inferred via the universal biconditional elimination rule. For all y, if y were rich, then y is taking a plane can be inferred via the universal biconditional elimination rule. For all y, if y were a lawyer, then y is a police officer can be inferred via the universal biconditional elimination rule. For all y, y will not take a plane can be inferred via the universal biconditional elimination rule.