Numbers

Natural numbers

[math]\displaystyle{ \mathbb{N} }[/math] denotes the set of positive integral numbers:

[math]\displaystyle{ \mathbb{N} := \{1,2,3,...\} }[/math]

[math]\displaystyle{ \mathbb{N}_{0} := \mathbb{N} \cup \{0\} }[/math]

We say that [math]\displaystyle{ \mathbb{N}_{0} }[/math] is the set of all natural numbers.