A logic exercise by Lewis Carroll: What conclusion can be drawn from these premises?

1. No shark ever doubts that it is well fitted out.
2. A fish that cannot dance a minuet is contemptible.
3. No fish is quite certain that it is well fitted out unless it has three rows of teeth.
4. All fishes except sharks are kind to children.
5. No heavy fish can dance a minuet.
6. A fish with three rows of teeth is not to be despised.