A condenser output as a one-block source #
The equivalence between an output value and its one-coordinate tuple preserves each point mass. Applying it to the actual output and every conditional witness retains the original statistical distance bound.
theorem
Algebraic.Cutwidth.Extractor.Internal.weightedStrongSeededCondenser_singleton
{X : Type u_1}
{Earlier : Type u_2}
{α : Type u_3}
[Fintype X]
[Fintype Earlier]
[Fintype α]
{C : X → Earlier → α}
{Kin Kout : ℕ}
{ε : ℝ}
(cond : WeightedStrongSeededCondenser C Kin Kout ε)
(p : X → ℝ)
(probability : IsProbabilityWeight p)
(cap : CappedWeight p Kin)
:
∃ (q : Earlier → (Fin 1 → α) → ℝ),
(∀ (y : Earlier), IsBlockSource (q y) Kout) ∧ weightDist (weightedSeededOutput p fun (x : X) (y : Earlier) (x_1 : Fin 1) => C x y) (seedFamilyWeight q) ≤ ε