Floor
From specialfunctionswiki
The floor function $\mathrm{floor} \colon \mathbb{R} \rightarrow \mathbb{Z}$ is defined by $$\lfloor x \rfloor = \max \left\{y \in \mathbb{Z} \colon y \leq x \right\},$$ i.e., it is the largest integer less than or equal to $x$. It is also sometimes denoted by $\lfloor x \rfloor$.
Graph of $\mathrm{floor}$.
