Follow-up Comment #1, bug #278 (project tex4ht): The mathml- option doesn't insert extra <mrow> elements, so it produces valid MathML code. Semantically, <mrow> should be used to enclose the operator and the fenced code. The MathML code in this case is inserted using ht-fonts mechanism in tex4ht DVI processor. It would be best if it was possible to insert some code in the DVI post-processing in the case when there is unclosed delimiter.
This is the relevant code from tex4ht-mathml.tex: \:CheckOption{mathml-} \if:Option \Configure{MathClass}{4}{*}{<\a:mathml mo\Hnewline \mml:class="MathClass-open">} {</\a:mathml mo>}{} \Configure{MathClass}{5}{*}{<\a:mathml mo\Hnewline \mml:class="MathClass-close">} {</\a:mathml mo>}{} \else \Log:Note{for sources failing to produce clean mathml code, try the command line option `mathml-'}% \Configure{MathClass}{4}{*}{<\a:mathml mrow ><\a:mathml mo\Hnewline \mml:class="MathClass-open">} {</\a:mathml mo><\a:mathml mrow>}{} \Configure{MathClass}{5}{*}{</\a:mathml mrow><\a:mathml mo\Hnewline \mml:class="MathClass-close">} {</\a:mathml mo></\a:mathml mrow>}{} \fi _______________________________________________________ Reply to this item at: <http://puszcza.gnu.org.ua/bugs/?278> _______________________________________________ Message sent via/by Puszcza http://puszcza.gnu.org.ua/