What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is not late. It is windy if and only if it is late. Joseph is writing a letter if and only if it is windy.
If it is windy, then it is late. If Joseph writes a letter, then it is windy. If it is late, then it is windy. If it is windy, then Joseph is writing a letter. It is not windy.