# Can we automatically catch some common formatting errors?

The one I've been seeing by far the most often occurs when users new to MathJax write something like {$a,b,c$} instead of $\{a,b,c\}$. Would it be possible to look for instances of {$ and $} and gently suggest that "If you are trying to write braces (curly brackets) in mathematics mode, please use \{ and \}"? It would also pay to check for the strings "sin", "cos", "tan", "dim", etc. that are not preceded by a backslash.