III. Propositional and First-Order Logic
(and other things, like Syntax vs. Semantics)

1. Syntax vs. Semantics
   • Note: Some of the items that used to be on the page you are now reading have migrated to this new page, which is just on syntax and semantics, whereas the current page is now just on FOL.

2. Some references on translating from English to logic

3. Shapiro, Stuart C., "Foundations of Logic and Inference"
   • Website that contains links to articles, tutorials, and Lisp code for first-order predicate logic.

4. Some references on logic and AI:
   • Rapaport, William J. (1992), "Logic", in Stuart C. Shapiro (ed.), Encyclopedia of Artificial Intelligence, 2nd edition (New York: John Wiley): 851-853

   • Rapaport, William J. (1992), "Logic, Predicate", in Stuart C. Shapiro (ed.), Encyclopedia of Artificial Intelligence, 2nd edition (New York: John Wiley): 866-873

   • Rapaport, William J. (1992), "Logic, Propositional", in Stuart C. Shapiro (ed.), Encyclopedia of Artificial Intelligence, 2nd edition (New York: John Wiley): 891-897

5. Rules for SEND and RETURN

6. Many-Valued Logics

7. Mental Models
   • Some on-line references about Johnson-Laird's "mental-model" theory of how humans reason, and on the controversy between his theory and Rips's "syntactic" theory.

8. Clause Form (pdf file)
   Clause Form (ps file)

9. Resolution Proof in Natural-Deduction Format

10. Unification Algorithm (PDF file)

11. Unification Example (PDF file)

12. Further Thoughts on Unification