# How to teach make4ht to understand newcommand properly?


Question: Is there any way to fix this issue?

• it is impossible to debug an image, please add a code block with a complete small document that makes that image Dec 1 '19 at 22:55
• in particular, how are you calling \coeffX Dec 1 '19 at 22:56
• I call it as: \coeffX{m}{t}{j}
– PKK
Dec 1 '19 at 22:57
• @DavidCarlisle, Source Files are added.
– PKK
Dec 1 '19 at 23:04
• a small inline example is much better than a link to an external site, the question here is archived forever but the external link has fewer guarantees, Dec 1 '19 at 23:08

This is a common issue regarding sub- and superscripts in TeX4ht. The _ and ^ characters are not active in the preamble, so commands defined here don't work correctly. It is best to use the \sp and \sb commands instead:
\newcommand \coeffX [4][X]{\mathbf{#1}\sb{#2,#3}(#4)}