# Question about an equation from LaTeX Search

I was randomly looking in LaTeX Search and I found the following formula:

P\left( {E_n^{\left( d \right)} ,{\text{i}}{\text{.o}}{\text{.}}} \right) = 0\quad {\text{or}}\quad {\text{1}}

In it there is this term:

{\text{i}}{\text{.o}}{\text{.}}}

Is there any reason for using 3 \text commands and not using a single one?

As these are equations from scientific papers it seems to me peculiar for someone to do this from ignorance so I can guess that there must be a reason.

• I think that it is not that peculiar or, at least, probably not that unusual. Did you try compiling and comparing the two cases? I can't see any obvious visual difference. I wonder if this might be the product of an conversion tool e.g. from some other kind of mark-up or some other programme. (Not like this but when I convert Word forms to LaTeX, the code is fully of pointless things.) – cfr Nov 16 '14 at 0:50
• I would guess there is no reason:-) \left(d\right) should be just (d) as well. – David Carlisle Nov 16 '14 at 0:50
• @DavidCarlisle I saw that too, but the 3 \text commands were far more peculiar! @cfr I didn't know about conversion tools so it is interesting now that you mentioned it! Anyway thank you both very much. :) – Adam Nov 16 '14 at 1:08
• @Adam You can only ping one person at once. (So you did not, in fact, ping me at all...) – cfr Nov 16 '14 at 2:46
• @cfr Sorry about that! I will keep it in mind! – Adam Nov 16 '14 at 2:59

Just compare the two results and you will see that there is no difference. The letters are set in their own boxes as can be seen in the first (original) example, but I can't think of a use case for that.

The code looks as if it was not written manually. Maybe some conversation tool. I added a version on how I would type it. Just compare:

% arara: lualatex

\documentclass{article}
\usepackage{mathtools}
\usepackage{lua-visual-debug}

\begin{document}
$P\left( {E_n^{\left( d \right)} ,{\text{i}}{\text{.o}}{\text{.}}} \right) = 0\quad {\text{or}}\quad {\text{1}}$
$P\Bigl(E_n^{(d)}, \text{i.o.}\Bigr) = 0 \quad \text{or} \quad 1$
\end{document}