[Scott Finnie #21 wrote:](https://forum.azimuthproject.org/discussion/comment/16266/#Comment_16266)
> It does, however, raise another minor question for me: why use ≤ to mean "is less than" instead of
We don't. We use \\(\le\\) to mean "less than or equal to". In a preorder, \\(x = y\\) implies \\(x \le y\\). So, the case of equality is always included in \\(\le\\).