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_7, x_7 will sleep if and only if x_7 is a janitor. If it is overcast, then Patricia is sleeping. It is overcast or Patricia is a janitor.
If Patricia cooks, then it is overcast can be inferred via the rewriting rule. For all x_7, if x_7 sleeps, then x_7 is a janitor can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 were a janitor, then x_7 is sleeping can be inferred via the universal biconditional elimination rule.