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: If Patricia were a doctor, then Charles is not working. It is snowing or Patricia is a doctor. Charles is working.
Patricia is not a doctor can be inferred via the modus tollens rule. If Patricia were not a doctor, then it is snowing can be inferred via the rewriting rule.