What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Richard were a poet, then Thomas is reading a book. Sarah is playing squash if and only if Thomas is reading a book. James is drinking water if and only if Sarah is playing squash.
If Sarah plays squash, then Thomas is reading a book. If James drinks water, then Sarah is playing squash. If Thomas reads a book, then Sarah is playing squash. If Sarah plays squash, then James is drinking water.