A relational symbol combining less-than with equality, indicating "less than or equal to" with a slanted equals line.
Examples
Basic inequality with less than or equal to
x \leqslant y \leqslant z
Function domain constraint
f(x) = \sqrt{x^2 - 4} \text{ for } x \leqslant -2 \text{ or } x \geqslant 2
Sequence bound comparison
a_n \leqslant M \text{ for all } n \in \mathbb{N}