Bob is huge. Bob is big. Erin is short. Erin is thin. Dave is nice. Gary is dull. Gary is poor. If someone is not high then they are dull. If someone is not bad then they are quiet. If someone is nice then they are kind. If someone is kind and not rough then they are wealthy. If someone is dull and not high then they are sad. If someone is short and thin then they are rough. If someone is rough and not kind then they are poor. All quiet people are smart. 
Bob is not sad.