TeX4ht shows error "v'^\dagger_i " while using align environment but not in inline equation

Question

TeX4ht shows error "v'^\dagger_i " while using align environment but not in inline equation.

The pdflatex not shown error both inline and align environment

The Tex4ht error as follow: ! Double superscript. \s:p

l.6 \end{align}

Answer 1

TeX4ht needs proper grouping for subscripts and superscripts, especially in the MathML mode. So when you use multiple tokens, like v' as a part of your expression, you need to add braces:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
${v'}^{\dagger}_{i} $

\begin{align}
{v'}^\dagger_i  = v
\end{align}
\end{document}