English
Let p be a predicate on ι and f : Subtype p → α. Then the infimum of f equals the infimum over i of f restricted to i with witness h: p i.
Русский
Пусть p — предикат на ι и f : Subtype p → α. Тогда ⨅ f = ⨅_{i} ⨅_{h : p i} f⟨i,h⟩.
LaTeX
$$$$\bigwedge_{x : Subtype p} f(x) = \bigwedge_{i} \bigwedge_{h : p i} f(i,h).$$$$
Lean4
theorem iInf_subtype : ∀ {p : ι → Prop} {f : Subtype p → α}, iInf f = ⨅ (i) (h : p i), f ⟨i, h⟩ :=
@iSup_subtype αᵒᵈ _ _