Why is it that whatever I type in the superscript turns into gibberish?
As pointed out by @Phelype Oleinik in comment 1, you do not want to have the numbers inside the
\mathbb. To accomplish this in LyX, I suggest the following:
- ctrl + m to enter math mode.
\mathbb<space>to start the blackboard font (or click on it in the font toolbar).
- Type "R".
<space>, or alternatively to exit
\mathbbbut to stay inside the math inset.
^to go into superscript.
- Type what you want in the superscript.
The important step is 4. If you do not do 4, the next thing you type will be inside
\mathbb, which is not what you want. There is a slight, but important, visual cue that the nesting is not what you want: look at the red frames. From your screenshot, they show that you are nested at a few levels, when probably you only want to see one level of nesting.
By the way, great question for your first question on this site! You title is clear, you show a screenshot that shows both the LyX and the underlying LaTeX, and your screenshot even gives a hint at what OS you're using. All of this information is useful.