What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Charles is not working or Thomas is cooking. Thomas is not climbing a mountain. Sarah is playing tennis if and only if Thomas is climbing a mountain. It is not snowing or Sarah is playing tennis. It is snowing or Charles is working.
Charles is working or Sarah is playing tennis. If Sarah plays tennis, then Thomas is climbing a mountain. If Thomas climbs a mountain, then Sarah is playing tennis. Sarah is not playing tennis.