# Proper notation for enumeration

Between these two options, is there a best practice notation for enumeration or are they both equivalently acceptable: $$\forall i = 0,1,\dots,n-1 \qquad (1)$$ $$\forall i \in \{0,1,\dots,n-1\} \qquad (2)$$

NS

• Btw, any relation with the English chess grandmaster? – Tal-Botvinnik May 16 '18 at 12:19

Both notations see widespread use in the literature. The second version has the downside of being slightly more cumbersome to write down (and to typeset using $\LaTeX$) but it offers the advantage of being more versatile (in that it carries over to any, potentially infinite, index set) and, arguably, more formal.
In my personal opinion, both are OK, but the $\forall$ sign is reduntant. I'd rather write
"for $i=0,\dots,n$".