C251 Foundations of Digital Computing
Dana Vrajitoru
C251 Homework 6
Due date: Wednesday, October 8, 2025.
 Proofs, Proofs with Quantifiers
Solve the following exercises from the textbook:
- Chapter 3.2, pages 66-67, exercises 2, 4, 6 using the proof by
contraposition, 7, 8 b, c.
 - Chapter 3.3, page 69, exercises 1, 2 c, d.
 
Notes:
- The page numbers refer to what is displayed at the top of the
pages and not the count shown above the file.
 - You can use exercises and theorems proved in the lecture and in
the textbook to solve homework exercises when applicable.