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_2, x_2 will not work. There is at least one x_2 for which if x_2 cooks, then x_2 is not a sailor. For all x_2, x_2 will go running if and only if x_2 will work. For all x_2, x_2 will go running or x_2 is a sailor.
For all x_2, if x_2 goes running, then x_2 is working can be inferred via the universal biconditional elimination rule. For all x_2, if x_2 works, then x_2 is running can be inferred via the universal biconditional elimination rule. For all x_2, x_2 will not go running can be inferred via the universal biconditional elimination rule.