What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Michael is playing tennis if and only if Charles is making tea. Charles is making tea or Michael is not playing tennis. For all x_17, x_17 will not play tennis.
If Michael plays tennis, then Charles is making tea. If Michael plays tennis, then Charles is making tea. If Charles makes tea, then Michael is playing tennis.