Double subscript with a hat

Question

Hope you are doing well.

I am having some issues with double subscripts and use of hat command.

Basically I want to achieve something like this:

{{\hat{Y}}_r}_i^t

But I get the "Double subscript" error. If I take off the \hat{} and do {Y_r}_i^t there is no error. I can also put the r inside \hat like {\hat{Y_r}}_i^t, that works, but it is not what I want

I don't really understand why the hat with subscript causes this issue, or how to circumvent it. I am using overleaf.

Thank you.

Answer 1

This came up just recently,(somewhere) it's a result of the way the basic tex code unwinds atoms that just have a single character in their base. If you add a {} (or anything, more or less) you get the expected behaviour.

\documentclass{article}
\begin{document}
${\hat{Y}_r{}}_i^t$
\end{document}