Walk 2

This walk is an introduction into the world of numbers. It explains

• the set $\Bbb{N}$ of the natural numbers,
• the set $\Bbb{Z}$ of the integers,
• the set $\Bbb{Q}$ of the rational numbers,
• the set $\Bbb{R}$ of the real numbers,
• the set $\Bbb{C}$ of the complex numbers and
• the set $\Bbb{H}$ of the quaternions.

• UNIT
  Natural Numbers and the Principle of Induction