tex.math.delims — Should equations output for processing by TeX be surrounded by math mode delimiters?
For compatibility with DSSSL based DBTeXMath from Allin Cottrell you should set this parameter to 0.
This feature is useful for print/PDF output only if you use the obsolete and now unsupported PassiveTeX XSL-FO engine.
You can also use the <?dbtex delims?> processing
instruction to control whether delimiters are output.