Bob is not smart. Charlie is quiet. Dave is furry. Fiona is big. If someone is not big then they are not red. If someone is smart and red then they are quiet. All quiet, big people are not green. All green people are furry. If someone is smart and not big then they are quiet. If someone is not red then they are quiet. If someone is not furry then they are rough. If someone is not furry and not rough then they are not smart.
Dave is not rough.