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 carpenter. For all x, x will play a game if and only if x is a mechanic. There is at least one x for which x is a mechanic.
For all x, if x plays a game, then x is a mechanic can be inferred via the universal biconditional elimination rule. For all x, if x were a mechanic, then x is playing a game can be inferred via the universal biconditional elimination rule.