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: There is at least one x_7 for which if x_7 makes tea, then x_7 is not working. For all x_7, x_7 will play a game. For all x_7, x_7 will play a game if and only if x_7 will work.
For all x_7, if x_7 plays a game, then x_7 is working can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 works, then x_7 is playing a game can be inferred via the universal biconditional elimination rule.