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_12, if x_12 were a bartender, then x_12 is playing tennis. For all x_12, if x_12 were a nurse, then x_12 is not sleeping. For all x_12, x_12 is a bartender or x_12 will sleep. For all x_12, x_12 will play tennis if and only if x_12 is a soldier. For all x_12, x_12 is not a soldier.
For all x_12, if x_12 plays tennis, then x_12 is a soldier can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 were a soldier, then x_12 is playing tennis can be inferred via the universal biconditional elimination rule. For all x_12, x_12 will not play tennis can be inferred via the universal biconditional elimination rule.