The finite shared-control circuit lower bound #
Actual narrow and wide conjunction messages receive their separate information charges. A single averaged cut preserves a common triple fraction of both classes. The old affine count and the new shared-control count eliminate both gate classes.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Shared.sender_le_size_of_refined_messages
{n K : ℕ}
(c : Circuit Aggregate.Geometry.signature n 1)
(hK : 0 < K)
(free : RectangleFree (c.outputFunction Aggregate.Geometry.interpretation 0) K)
(freeNot : RectangleFree (fun (x : Cslib.BitString n) => !c.outputFunction Aggregate.Geometry.interpretation 0 x) K)
(U : Finset (Fin n))
(large : 2 * K ≤ 2 ^ Uᶜ.card)
:
(1 - Joint.overlapPenalty) * ↑U.card ≤ ↑c.size + 1 + Real.logb 2 ↑K - Joint.gateSaving * ↑(Joint.retainedTwo c.program U).card - wideSaving * ↑(Joint.retainedWide c.program U).card
The actual sending side receives separate narrow and wide message savings.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Shared.input_le_size_of_triple_entropy
{n a K : ℕ}
(c : Circuit Aggregate.Geometry.signature n 1)
(ha : 3 ≤ a)
(han : a ≤ n)
(hK : 0 < K)
(free : RectangleFree (c.outputFunction Aggregate.Geometry.interpretation 0) K)
(freeNot : RectangleFree (fun (x : Cslib.BitString n) => !c.outputFunction Aggregate.Geometry.interpretation 0 x) K)
(large : 2 * K ≤ 2 ^ (n - a))
:
(1 - Joint.overlapPenalty) * ↑a ≤ ↑c.size + 1 + Real.logb 2 ↑K - Joint.tripleRetention n a * (Joint.gateSaving * ↑(Aggregate.Geometry.Shared.exactTwo c.program).card + wideSaving * ↑(Joint.retainedWide c.program Finset.univ).card)
One averaged cut retains the same triple fraction of both original gate classes.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Shared.input_le_size_of_entropy
{n K : ℕ}
(c : Circuit Aggregate.Geometry.signature n 1)
(hK : 0 < K)
(disperse : FlatSumsetDisperser (c.outputFunction Aggregate.Geometry.interpretation 0) K)
(range : Nat.clog 2 K + 4 ≤ n)
:
(1 - Joint.overlapPenalty) * (↑n - ↑(Nat.clog 2 K) - 1) ≤ ↑c.size + 1 + Real.logb 2 ↑K - receiverRetention n (Nat.clog 2 K) * (Joint.gateSaving * ↑(Aggregate.Geometry.Shared.exactTwo c.program).card + wideSaving * ↑(Joint.retainedWide c.program Finset.univ).card)
A logarithmic receiving side gives the finite refined information inequality.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Shared.size_lowerBound_of_sumsetDisperser
{n K : ℕ}
(c : Circuit Aggregate.Geometry.signature n 1)
(hK : 0 < K)
(disperse : FlatSumsetDisperser (c.outputFunction Aggregate.Geometry.interpretation 0) K)
(range : Nat.clog 2 K + 4 ≤ n)
:
have k := Nat.clog 2 K;
have a := receiverRetention n k;
(1 - Joint.overlapPenalty) * (↑n - ↑k - 1) + a * (Joint.gateSaving / 2 + 3 * wideSaving / 2) * ↑n - 2 * a * wideSaving * ↑k - 1 - Real.logb 2 ↑K ≤ (1 + a * wideSaving) * ↑c.size
The unrestricted signed basis satisfies the shared-control finite lower bound.