Example:
x^2, x_1^2, x^{(n)}_{22}, ^{16}O^{2-}_{32}, x^{y^{z^a}}, x^{y_z}
\[
X^2, x_1^2, x^{(n)}_{22}, ^{16}o^{2-}_{32}, X^{y^{z^a}}, X^{y_z}
\]
If you need to use text as a corner label, first put the text in \mbox{} text mode, plus the command to change the text size, for example:
\partial f_{\mbox{\tiny 极大值}}
Display as: \ (\partial f_{\mbox{\tiny max}}\)
When the position of the corner mark is not obvious, you can force change the size or level of the angle, the distance is as follows:
y_N, y_{_N}, y_{_{\scrptstyle N}
Shown as:
\[
Y_n, Y_{_n},y_{_{\scriptstyle N}}
\]
The first output is normal output, but the output effect is not obvious; the second is to change the primary angle to a two-level angle, and the font to automatically change to a two-level corner font; The third one changes the first-level corner to a two-level corner label, but forces the font to be a one-level corner font.