CSCI 301 L11 Worksheet

Lecture 11 - Exercises

Part A - Proofs with Sets

  1. Prove that \(\{12n : n \in \mathbb{Z}\} \subseteq \{2n: n \in \mathbb{Z}\} \cap \{3n: n \in \mathbb{Z}\}\).
  2. Suppose \(A, B,\) and \(C\) are sets. Prove that if \(B \subseteq C\), then \(A \times B \subseteq A \times C\).
  3. Supoose \(A, B,\) and \(C\) are sets. Prove that \(A \cap (B \cup C) = (A \cap B) \cup (A \cap C)\).
  4. Prove that if \(A\) and \(B\) are both sets with universal set \(U\), then \(\overline{A \cap B} = \overline{A} \cup \overline{B}\).