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: William is not reading a book or Joseph is a police officer. William is reading a book. It is not cloudy or it is late. John is working. If Joseph were a police officer, then John is not working.
Joseph is not a police officer can be inferred via the modus tollens rule. William is reading a book and John is working can be inferred via the conjunction rule. John is working and William is reading a book can be inferred via the conjunction rule.