Bob is big. Bob is blue. Bob is furry. Bob is quiet. Bob is not red. Bob is rough. Bob is white. Dave is furry. Dave is red. Dave is rough. Dave is not white. Fiona is blue. Fiona is quiet. Fiona is red. Fiona is rough. Fiona is white. If someone is big and not quiet then they are rough. If someone is not white and not blue then they are red. If someone is not rough then they are not big.
Dave is not blue.