English
In the same setting, the ceil map is the smallest integer not less than a: for every a, ⌈a⌉ is the least integer z with a ≤ z.
Русский
Аналогично, функция ceil — наименьшее целое число, не меньшее a: для каждого a ⌈a⌉ — наименьшее z ∈ ℤ с a ≤ z.
LaTeX
$$$\forall a \in \alpha,\; \lceil a \rceil = \min\{ z \in \mathbb{Z} \mid a \le z \}.$$$
Lean4
/-- `Int.ceil a` is the smallest integer `z` such that `a ≤ z`. It is denoted with `⌈a⌉`. -/
def ceil : α → ℤ :=
FloorRing.ceil