What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Mary cooks, then it is overcast. James is reading a book if and only if Mary is cooking. If it is overcast, then Mary is cooking.
Mary is cooking if and only if it is overcast. It is overcast if and only if Mary is cooking. If James reads a book, then Mary is cooking. If Mary cooks, then James is reading a book.