What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_18, x_18 will play squash. There is at least one x_18 for which x_18 is not a sailor. For all x_18, if x_18 were a sailor, then x_18 is sleeping. For all x_18, if x_18 sleeps, then x_18 is a sailor. For all x_18, x_18 will sleep or x_18 is an office clerk.
There is at least one x_18 for which x_18 will not sleep. For all x_18, x_18 is a sailor if and only if x_18 will sleep. For all x_18, x_18 will sleep if and only if x_18 is a sailor.