Exercise E

Consider the following sentences:

1. There are at least four giraffes at the wild animal park.

2. There are exactly seven gorillas at the wild animal park.

3. There are not more than two Martians at the wild animal park.

4. Every giraffe at the wild animal park is a Martian.

Now consider each of the following collections of sentences. Which are jointly possible? Which are jointly impossible?

1. Sentences G2, G3, and G4

2. Sentences G1, G3, and G4

3. Sentences G1, G2, and G4

4. Sentences G1, G2, and G3