Date: Mon, 02 Dec 1996 14:42:51 GMT
Server: NCSA/1.4.2
Content-type: text/html
Subject: 415-Homework due Thursday, April 25, 1996 I introduced Predicate Logic at the last class and gave some examples of expressing English sentences, and an example (using the x>y predicate) to illustrate the use of quantifiers and show how existential quantifiers can be removed, using Skolem functions. I also defined clause form and talked about the transformations that will produce clause form when applied to any well formed formula in the predicate logic. At this point, you should read all of chapter 5 in Rich and Knight, paying particular attention to the discussion of proof procedures on p 113, the logic representation of 9 sentences on pages 134 to 136, the related comments, and the development of a proof. Also, note the sections on Resolution and Conversion to Clause form and the Unification algorithm. I will cover the latter topics in the next class. Homework Problems Rich and Knight Chapter 5, page 166. Do problems 1, 3, 4 and 8 (a) and (b). Notes: Problem 1. Here you need to make substitutions into the predicate logic forms of the facts, to prove hate(Marcus, Caesar) is True or False. ie you will be unifying. Problem 4. The sentence, "Anything anyone eats and isn't killed by is food" is ambiguous. Use the sense that if at least one person eats it and is not killed, it is food. Problem 8 (a), (b). Assume that a is a constant and x,y are variables.