CS 173: Skills list for first Written Test

• Logic and Proof techniques.
  • Write a simple direct proof, using familiar concepts, with good mathematical style. Make sure your statements are in logical order, starting with the given information and ending with what you needed to show.
  • Write a proof by cases
  • Write a proof by contradiction
  • Convert a claim to its contrapositive and prove that using direct proof.
  • Know the following standard ways to approach parts of a proof:
    • prove a universal claim by choosing a representative object of the appropriate type
    • prove an if/then statement by assuming whatever's in the hypothesis and proving the conclusion,
    • disprove a universal claim by giving a concrete counterexample.
    • prove an existential claim by giving specific values that make the claim true