What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_8, if x_8 sleeps, then x_8 is drinking water. For all x_8, if x_8 drinks water, then x_8 is sleeping. If Susan were a poet, then Charles is drinking water.
For all x_8, x_8 will sleep if and only if x_8 will drink water. For all x_8, x_8 will drink water if and only if x_8 will sleep.