English
The germ of a constant function b: α→β is the same as the germ of the constant germ function in Germ l β.
Русский
Жермен константы b есть константный жерм функции в Germ l β.
LaTeX
$$$\mathrm{const}(l, b) : \mathrm{Germ}(l, \beta)\quad\text{defined as }\mathrm{ofFun}(\lambda a. b).$$$
Lean4
/-- Germ of the constant function `fun x : α ↦ c` at a filter `l`. -/
@[coe]
def const {l : Filter α} (b : β) : (Germ l β) :=
ofFun fun _ => b