$~ \mathbb{N} \cup \left\{ 0 \right\} ~~ \leftarrow~~ \text{The set of integers each of which is greater or equal than zero} ~$
I want to know or create the alternative(s) of set of $~ \mathbb{N} \cup \left\{ 0 \right\} ~$
As I write $~ \mathbb{N} \cup \left\{ 0 \right\} ~$ using a pen in a paper, then a symbol of $~ \cup ~$ may sometimes be seen as letter U and the ambiguity seems happens.
Does anyone know it?
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Thought that $~ \mathbb Z_{\geq 0} ~$ may be the one of the answers .
Best Answer
I have seen $\mathbb N_0$ for this purpose.
However, I would simply include $0$ in $\mathbb N$ if that’s more useful. Then, using $\mathbb N^*$ for the set without $0$ is not uncommon, I think.
In any case, you should make your conventions explicit in the text, especially if the precise choice is relevant.