# CS 1571: Homework 7

## First-Order Logic (Chapters 8 and 9): Paper Problems (100 pts)

Assigned: November 4, 2008

Due: November 11, 2008

#### 1. Translation (50 pts)

Knowledge Base:

- Either (I have a sweet tooth and I like chocolate) or (I like chocolate and I like cake)

  Rules:

- If I like cake, then I also like Danish.
- If I like Danish, that implies I have a sweet tooth.
- If I have a sweet tooth and I like chocolate, then I am a chocoholic.

  Goal: I am a chocoholic

  (a) Rewrite the sentences above (from the last homework) using the formalism of First Order Logic.

  (b) Suppose your world consists of food and people, and that the rules above were true of all people, not just me. Rewrite this variation using FOL.

  #### 2. Translation for Forward and Backward Chaining (50 pts)

  GameX says it is criminal for a programmer to provide emulators to people. My friends don't have a GameX, but they use software EMULATOR1 that runs GameX games on their PC, which is written by SuperProgrammer, who is a programmer.

  (a) Write a knowledge base that formally represents the above using FOL, in a way that would allow you to use forward or backward chaining as your inference mechanism.

  #### Grading Criteria

  Clearly explain the predicates, functions and objects in your FOL representations, if they are not obvious. Also be sure to specify any relevant domains. For both problems, you are required to introduce predicates in your answer, that is, an answer expressed in propositional logic is not acceptable.