Propositional Inference: Resolution

CSC 261 - Artificial Intelligence - Weinman



Answer the following questions. Record your answers in your Reading Journal.
  1. Give an interpretable sentence in English (corresponding to how one might read aloud a sentence of propositional logic ) that is
    1. valid, and a sentence that is
    2. satisfiable, and one last sentence that is
    3. unsatisfiable.
    For example, "The weather is rainy and cold" is a propositional assertion phrased in English, rather than the more symbolic R ∧ C. Briefly explain why each of your sentences meets the definition of these terms.
  2. In your own words, briefly describe the resolution rule for an inference algorithm.
  3. Select a sentence from today's reading that you feel best illustrates the relationship between CNF and resolution for inference. Briefly explain why you chose this sentence.
  4. Suppose your neighbor in class forgot to read the text for today. How would you begin to explain this statement to them (i.e., why it's true): "two clauses resolve to yield the empty clause, in which case KB entails α." (p. 254, middle)1

Footnotes:

1Naturally, you would only do this after you remind them how awesome and useful it is to prepare for class. Of course, if everyone forgets, then everyone is up a creek. (We'll learn how to express that in logic soon.)