If you want more practice in translating sentences into first order predicate logic notation, try these exercises. You can check your work using the Symbolic Logic Interpreter . (Note: To run the Symbolic Logic Interpreter, use Firefox or Mozilla, and enable JavaScript.)

Represent each of the following sentences as a first-order predicate logic sentence.

1. All frogs are amphibians.
2. No frogs are insects.
3. Kermit is a frog.
4. Gandalf is not a frog.
5. Some reptiles are large.
6. Some cats are not lazy.
7. Some dogs are brown.
8. Some black dogs are large.
9. No purple insects are wise.
10. Aragorn loves Arwen.
11. Bob does not like Anne.
12. All cats purr.
13. All big dogs bark.