What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is not overcast. It is cold or it is late. It is not cold. It is overcast if and only if David is excited.
It is late. It is not overcast and it is not cold. It is not cold and it is not overcast. If it is overcast, then David is excited. If David were excited, then it is overcast. David is not excited.