Last modified: 2012-04-11 07:52:20 UTC
Using texvc \mathbb{1} gives the same as \nVdash, MathJax just outputs 1. Other fonts could be abused as well. This bug can probably be closed as WONTFIX, but it should be documented somewhere.
Just if someone doesn't believe that anything that can be abused will be abused: [[Propositional directed acyclic graph]] and [[de:Bayer-Verfahren]] both use \mathcal 5 for a triangle.
eh, yeah, I don't think we should fix this. It's not a proper LaTeX math definition, it's making use of a hack to display something different from what you have written.
Some statistics: I scanned the XML dump for dewiki using /math(cal|bb) *(\{[^}0-9]*)?[0-9]/ and found: * 2 documentation pages (!) * 1 article, where MathJax' output would have been correct (\mathbb {R^3}) * 5 articles (mostly chemistry), where this syntax was abused to produce some triangle 5 out of 1.39 million articles are almost nothing, there have been changes with a worse backwards compatibility. If someone is going to create a list of the differences between MathJax and texvc, this should be mentioned, but otherwise it probably can be ignored, so closing WONTFIX.