Anne is white. Bob is green. Bob is kind. Bob is not red. Dave is rough. Dave is young. Fiona is green. Fiona is red. Fiona is rough. Fiona is white. Fiona is young. Green people are blue. If Dave is kind and Dave is white then Dave is green. All kind people are white. All young people are red. If Bob is green then Bob is kind. All rough, red people are kind. If Bob is kind and Bob is red then Bob is not white. If someone is young and not rough then they are not kind. If someone is blue and not green then they are red.
Dave is not white.