The render result of \dots and \cdots is the same

[YiNiCoo]

The render result of \dots and \cdots is the same

[dpvc]

To clarify, I'm assuming you mean for x, \dots, y, as they should be \cdots for x+\dots+y. Note that x\dots y does produce \ldots, so it seems not to recognize the situation for commas properly.

[dpvc]

This is due to

https://github.com/mathjax/MathJax-src/blob/1e1a30f0a89e52fa7764dbb510763145a4da49f1/ts/input/tex/base/BaseItems.ts#L750-L751

This is because the texClass hasn't been set for the elements yet at this point, and so the default REL class is what is found, so it always uses \cdots. @zorkow, we may need to do another post-filter for this, since the texClass is not set properly until the end of the parsing. Alternatively, the getTexClass() method could be modified to look up the TeX class from the operator dictionary when the node is an mo.

There is a second usage of getTexClass() in BaseMethods.ts that probably needs fixing as well.

[dpvc]

I'm moving this to the main MathJax issue tracker, so it can be found more easily.