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, if x plays a game, then x is a writer. There is at least one x for which if x drives a car, then x is working. For all x, x will play a game if and only if x will work. For all x, x will drive a car or x is not a writer.
For all x, if x were a writer, then x is driving a car can be inferred via the universal rewriting rule. For all x, if x plays a game, then x is working can be inferred via the universal biconditional elimination rule. For all x, if x works, then x is playing a game can be inferred via the universal biconditional elimination rule.