English
If f and g are minimal on s at a, then their pointwise infimum is minimal on s at a.
Русский
Если f и g минимальны на s в a, то их инфimum по x минимален на s в a.
LaTeX
$$$\\mathrm{IsMinOn}(f,s,a) \\land \\mathrm{IsMinOn}(g,s,a) \\Rightarrow \\mathrm{IsMinOn}(\\lambda x. f(x) \\otimes g(x), s, a)$$$
Lean4
theorem inf (hf : IsMinOn f s a) (hg : IsMinOn g s a) : IsMinOn (fun x => f x ⊓ g x) s a :=
IsMinFilter.inf hf hg