The short answer is: no, not at the moment.
The reason is that allowing HTML to be passed via a submitted form presents a security problem - Cross Site Scripting Vulnerability, in particular.
I know you're writing the computation code, but that doesn't stop an attacker from submitting replacement or additional computation code.
However, there will be a need to provide this feature at some stage. We'll probably go the way of "bbcode" - where you can't write HTML, but you can write some special tagging that gets translated into safe HTML code.
E.g. this is bold