What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, x_9 is not a bartender. Elisabeth is a sailor if and only if David is making tea. For all x_9, x_9 will make tea if and only if x_9 is a bartender.
If Elisabeth were a sailor, then David is making tea. If David makes tea, then Elisabeth is a sailor. For all x_9, if x_9 makes tea, then x_9 is a bartender. For all x_9, if x_9 were a bartender, then x_9 is making tea. For all x_9, x_9 will not make tea.