What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it snows, then Jennifer is not writing a letter. Charles is a sailor if and only if it is snowing. It is cold if and only if Charles is a sailor. Jennifer is writing a letter.
It is not snowing. If Charles were a sailor, then it is snowing. If it is cold, then Charles is a sailor. If it snows, then Charles is a sailor. If Charles were a sailor, then it is cold.