What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it is sunny, then Sarah is a carpenter. If Thomas were a writer, then it is sunny. If Sarah were a carpenter, then Thomas is a writer. If it is sunny, then Thomas is a writer.
If it is sunny, then Thomas is a writer. If Thomas were a writer, then Sarah is a carpenter. If Sarah were a carpenter, then it is sunny. Thomas is a writer if and only if it is sunny. It is sunny if and only if Thomas is a writer.