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_5, if x_5 sleeps, then x_5 is a mechanic. For all x_5, x_5 will sleep if and only if x_5 is a mechanic.
For all x_5, if x_5 sleeps, then x_5 is a mechanic can be inferred via the universal biconditional elimination rule. For all x_5, if x_5 were a mechanic, then x_5 is sleeping can be inferred via the universal biconditional elimination rule.