Catch-up Session 5

COMP109 Catch-up+Sessions 2020-11-09

Example 1

$A=\{1,2,7,8,9\}, B=\{x\in A\vert x \text{ is odd}\}$

Where:

$C=A-B=A\cap B$

Therefore:

$B=\{1,7,9\}$

$C=\{2,8\} = \{x\in A \vert x \notin B\}$

Proving Identities

To prove an identity you would consider the sections of a Venn diagram and consider each of the four cases. These cover all of the locations in the Venn diagram.