English
Same as above: Multipliable f iff Tendsto f cofinite (nhds 1).
Русский
То же самое: умножимость f эквивалентна стремлению f к 1 по кофинитному фильтру.
LaTeX
$$$\\displaystyle \\text{Multipliable}(f) \\iff \\text{Tendsto}(f,\\text{cofinite},(\\mathcal{nhds} 1))$$$
Lean4
/-- Let `G` be a complete nonarchimedean multiplicative abelian group. Then a function `f : α → G`
is unconditionally multipliable if and only if it tends to one on the filter of cofinite sets. -/
@[to_additive /-- Let `G` be a complete nonarchimedean additive abelian group. Then a function
`f : α → G` is unconditionally summable if and only if it tends to zero on the filter of cofinite
sets. -/
]
theorem multipliable_iff_tendsto_cofinite_one [CompleteSpace G] (f : α → G) :
Multipliable f ↔ Tendsto f cofinite (𝓝 1) :=
⟨Multipliable.tendsto_cofinite_one, multipliable_of_tendsto_cofinite_one⟩