Infinite sum and products that converge uniformly on a set #
This file defines the notion of uniform convergence of infinite sums and products of functions, on a given family of subsets of their domain.
It also defines the notion of local uniform convergence of infinite sums and products of functions on a set.
Uniform convergence of sums and products #
HasProdUniformlyOn f g 𝔖
means that the (potentially infinite) product ∏' i, f i b
for b : β
converges uniformly on each s ∈ 𝔖
to g
.
Equations
- HasProdUniformlyOn f g 𝔖 = HasProd (fun (i : ι) => (UniformOnFun.ofFun 𝔖) (f i)) ((UniformOnFun.ofFun 𝔖) g)
Instances For
HasSumUniformlyOn f g 𝔖
means that the (potentially infinite) sum ∑' i, f i b
for b : β
converges uniformly on each s ∈ 𝔖
to g
.
Equations
- HasSumUniformlyOn f g 𝔖 = HasSum (fun (i : ι) => (UniformOnFun.ofFun 𝔖) (f i)) ((UniformOnFun.ofFun 𝔖) g)
Instances For
MultipliableUniformlyOn f 𝔖
means that there is some infinite product to which
f
converges uniformly on every s ∈ 𝔖
. Use fun x ↦ ∏' i, f i x
to get the product function.
Equations
- MultipliableUniformlyOn f 𝔖 = Multipliable fun (i : ι) => (UniformOnFun.ofFun 𝔖) (f i)
Instances For
SummableUniformlyOn f s
means that there is some infinite sum to
which f
converges uniformly on every s ∈ 𝔖
. Use fun x ↦ ∑' i, f i x to get the sum function.
Equations
- SummableUniformlyOn f 𝔖 = Summable fun (i : ι) => (UniformOnFun.ofFun 𝔖) (f i)
Instances For
## Locally uniform convergence of sums and products
HasProdLocallyUniformlyOn f g s
means that the (potentially infinite) product ∏' i, f i b
for b : β
converges locally uniformly on s
to g b
(in the sense of
TendstoLocallyUniformlyOn
).
Equations
- HasProdLocallyUniformlyOn f g s = TendstoLocallyUniformlyOn (fun (I : Finset ι) (b : β) => ∏ i ∈ I, f i b) g Filter.atTop s
Instances For
HasSumLocallyUniformlyOn f g s
means that the (potentially infinite) sum
∑' i, f i b
for b : β
converges locally uniformly on s
to g b
(in the sense of
TendstoLocallyUniformlyOn
).
Equations
- HasSumLocallyUniformlyOn f g s = TendstoLocallyUniformlyOn (fun (I : Finset ι) (b : β) => ∑ i ∈ I, f i b) g Filter.atTop s
Instances For
MultipliableLocallyUniformlyOn f s
means that the product ∏' i, f i b
converges locally
uniformly on s
to something.
Equations
- MultipliableLocallyUniformlyOn f s = ∃ (g : β → α), HasProdLocallyUniformlyOn f g s
Instances For
SummableLocallyUniformlyOn f s
means that ∑' i, f i b
converges locally
uniformly on s
to something.
Equations
- SummableLocallyUniformlyOn f s = ∃ (g : β → α), HasSumLocallyUniformlyOn f g s
Instances For
If every x ∈ s
has a neighbourhood within s
on which b ↦ ∏' i, f i b
converges uniformly
to g
, then the product converges locally uniformly on s
to g
. Note that this is not a
tautology, and the converse is only true if the domain is locally compact.
If every x ∈ s
has a neighbourhood within s
on which b ↦ ∑' i, f i b
converges
uniformly to g
, then the sum converges locally uniformly. Note that this is not a tautology,
and the converse is only true if the domain is locally compact.
If every x ∈ s
has a neighbourhood within s
on which b ↦ ∏' i, f i b
converges uniformly,
then the product converges locally uniformly on s
. Note that this is not a tautology, and the
converse is only true if the domain is locally compact.
If every x ∈ s
has a neighbourhood within s
on which b ↦ ∑' i, f i b
converges
uniformly, then the sum converges locally uniformly. Note that this is not a tautology, and the
converse is only true if the domain is locally compact.