Mixed entropy inequalities for the large-fiber lower bound #
Scalar circuits retain both the marginal and shared-graph message estimates. For permutations, constant conjunction-output messages cost zero; output rank then gives two inequalities with the same narrow and wide gate counts.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Fiber.input_le_size_of_marginal_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)
:
↑n - ↑(Nat.clog 2 K) - 1 ≤ ↑c.size + 1 + Real.logb 2 ↑K - Shared.receiverRetention n (Nat.clog 2 K) * (Entropy.bitSaving * ↑(Aggregate.Geometry.Shared.exactTwo c.program).card + Shared.wideSaving * ↑(Joint.retainedWide c.program Finset.univ).card)
A logarithmic receiving side retains separate marginal narrow and wide savings.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Fiber.three_mul_input_add_marginal_le_two_mul_size
{n : ℕ}
(c : Circuit Aggregate.Geometry.signature n n)
(bijective : Function.Bijective (c.eval Aggregate.Geometry.interpretation))
(nonliteral :
∀ (i j : Fin n) (b : Bool), c.outputFunction Aggregate.Geometry.interpretation i ≠ fun (x : Fin n → Bool) => b ^^ x j)
(independent : Aggregate.Geometry.NonaffineComponents (c.eval Aggregate.Geometry.interpretation))
:
3 * ↑n + Entropy.bitSaving * ↑(Aggregate.Geometry.Shared.exactTwo c.program).card + Shared.wideSaving * ↑(Joint.retainedWide c.program Finset.univ).card ≤ 2 * ↑c.size
Nonaffine permutation outputs combine with the separate marginal message savings.
theorem
Algebraic.Cutwidth.Aggregate.Geometry.Fiber.three_sub_penalty_mul_input_add_joint_le_two_mul_size
{n : ℕ}
(c : Circuit Aggregate.Geometry.signature n n)
(bijective : Function.Bijective (c.eval Aggregate.Geometry.interpretation))
(nonliteral :
∀ (i j : Fin n) (b : Bool), c.outputFunction Aggregate.Geometry.interpretation i ≠ fun (x : Fin n → Bool) => b ^^ x j)
(independent : Aggregate.Geometry.NonaffineComponents (c.eval Aggregate.Geometry.interpretation))
:
(3 - Joint.overlapPenalty) * ↑n + Joint.gateSaving * ↑(Aggregate.Geometry.Shared.exactTwo c.program).card + Shared.wideSaving * ↑(Joint.retainedWide c.program Finset.univ).card ≤ 2 * ↑c.size
Nonaffine permutation outputs also retain the joint support-graph savings.