How do I put a <sup> tag inside a <sup> tag?

Question

I need to write the expression e to the -x square using HTML inside Freeplane. Can you please tell me how to do it? When I try to use one tag after another like this: f(x)=e^-x2 and hit OK, the program automatically transforms my code in f(x)=e^-x2.

Answer 1

You can do this with a span tag inside sup tag and CSS.

sup span {
vertical-align: super;
font-size: .8em;
}

<p>f(x)=e<sup>-x<span>2</span></sup></p>