I'm following along with Kreyszig's intro to functional analysis text, where he uses $X$ to indicate an abstract set, and often uses $x$ to indicate an element of $X$. I want to match his notation, but in a way that--when handwritten--makes a clear distinction between the upper and lower case letters. My normal lowercase $x$ is more curvy, but I feel like that's not enough, and adding serifs by hand for the big $X$ is too cumbersome. I did see a professor that just swiped a line across the top of an x-shape to indicate the big $X$ but that looked sloppy to me. Maybe I'm just being too anal about it, but I like my math writing to look good. Any suggestions?

I threw the functional-analysis tag on here because this is the context in which my question seems most relevant.

Edit: Consider that the cartesian product symbol $\times$ causes some interference as well.

  • $\begingroup$ You could also make the top angle in "X" smaller. $\endgroup$ – Alberto Takase Feb 4 at 9:28

One way I’ve seen others do this is to write the lowercase ‘x’ smaller, and write the uppercase ‘x’ bigger, with the end points extended in a line like this:

uppercase X

I apologize for the picture in advance. It seemed the easiest way to write the notation.

  • $\begingroup$ Thanks, yeah that's how I've been doing it, and it looks good, but it takes a lot of energy (relatively) to add those serifs on. $\endgroup$ – Zduff Feb 3 at 18:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.