English
The real-valued standard simplex stdSimplex Real ι is a closed set for finite ι.
Русский
Стандартный симплекс stdSimplex Real ι для конечного ι является замкнутым множеством.
LaTeX
$$$\mathrm{IsClosed}(\mathrm{stdSimplex}_{\mathbb{R}}(\iota))$$$
Lean4
/-- `stdSimplex ℝ ι` is closed. -/
theorem isClosed_stdSimplex : IsClosed (stdSimplex ℝ ι) :=
(stdSimplex_eq_inter ℝ ι).symm ▸
IsClosed.inter (isClosed_iInter fun i => isClosed_le continuous_const (continuous_apply i))
(isClosed_eq (continuous_finset_sum _ fun x _ => continuous_apply x) continuous_const)