I tried to define an \sp macro in LaTeX, to do something like this: \def\sp{\mathsf{span}} \[ \sp\{x\} \] \[ x^2 \] There is no problem with pdflatex, but evidently tex4ht uses \sp for something special. The first formula gives a parser error in firefox, and the second is not the simple power that it should be.
Compilation command: htlatex test.tex "xhtml,mathml,charset=utf-8" " -cmozhtf -utf8" \ "-cvalidate" -shell-escape It is not a big deal, since I am used to sometimes hitting macro names which are used internally. It just breaks the ambition that every latex doc compiles with tex4ht and is perceived as the same content by a human reader. -- :-- Hans Georg