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_7, x_7 is not a poet or x_7 is a politician. For all x_7, x_7 will not work. For all x_7, x_7 is a nurse if and only if x_7 will work. For all x_7, x_7 is a poet.
For all x_7, if x_7 were a nurse, then x_7 is working can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 works, then x_7 is a nurse can be inferred via the universal biconditional elimination rule. For all x_7, x_7 is not a nurse can be inferred via the universal biconditional elimination rule.