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_11, x_11 will go running if and only if x_11 will work. If Elisabeth doesn't work, then Joseph is a sailor. Elisabeth is not running.
For all x_11, if x_11 goes running, then x_11 is working can be inferred via the universal biconditional elimination rule. For all x_11, if x_11 works, then x_11 is running can be inferred via the universal biconditional elimination rule.