What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_7, if x_7 were a janitor, then x_7 is a police officer. There is at least one x_7 for which if x_7 were a sailor, then x_7 is a janitor. For all x_7, if x_7 were a mechanic, then x_7 is a sailor. For all x_7, if x_7 were an electrician, then x_7 is a mechanic.
For all x_7, if x_7 were an electrician, then x_7 is a sailor. There is at least one x_7 for which if x_7 were a sailor, then x_7 is a police officer. There is at least one x_7 for which if x_7 were a mechanic, then x_7 is a janitor.