Why the equation in the picture is true?
http://mathhelpforum.com/attachments...difference.png
Why the equation in the picture is true?
http://mathhelpforum.com/attachments...difference.png
$$\mathbb{N}_{\text{odd}} - \mathbb{N}_{\text{even}} = \mathbb{N}_{\text{odd}} \cap \left(\mathbb{N}_{\text{even}}\right)^c = \mathbb{N}_{\text{odd}} \cap \mathbb{N}_{\text{odd}} = \mathbb{N}_{\text{odd}} = \left\{ n \in \mathbb{N}_{\text{odd}}: n \text{ is not even} \right\}$$