CMPSCI 250: Introduction to Computation

Final Exam (Version A) Spring 2020

David Mix Barrington and Hia Ghosh

1 May 2020

Directions:

  Q1: 30 points
  Q2: 30 points
  Q3: 30 points
  Q4: 30 points
Total: 120 points

  • Question 1 (30): One day, Duncan went to the park and met his friends Becky, Cindy, Maggie, and Pushkin, so that the set S of dogs at the park was {b, c, d, m, p}. Define three unary predicates on S, so that for any dog x, GT(x) means “x got a treat”, RO(x) means “x ran off”, and SN(x) means “x sat nicely”.

  • Question 2 (20+10): Let Σ = {a, b, c, d, e} and let S be the language (aa + bb + cc + ddd + eee)*.

  • Question 3 (30): Let N be a λ-NFA with state set {1, 2, 3, 4, 5}, start state 1, only final state 4, and transitions (1, λ, 2), (1, b, 3), (2, a, 4), (2, λ, 5), (3, b, 5), (4, a, 3), (4, b, 5), and (5, &lambda, 4). This is the λ-NFA used in the 2:00 exam. The 8:00 exam had the transition (4, λ, 5) instead of (4, b, 5).

  • Question 4 (30): The following are fifteen true/false questions, with no explanation needed or wanted, no partial credit for wrong answers, and no penalty for guessing.

    Last modified 19 May 2020