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: Jennifer is an astronaut or Barbara is sleeping. For all x_12, x_12 is a nurse if and only if x_12 will play tennis. For all x_12, x_12 is not a nurse. For all x_12, if x_12 were an astronaut, then x_12 is playing tennis.
For all x_12, if x_12 were a nurse, then x_12 is playing tennis can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 plays tennis, then x_12 is a nurse 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.