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Project-declaredLean 4.31.0 · mathlib@fabf563a7c95

Sub l Infty Norm le

ArkLib.Lattices.CyclotomicModulus.sub_lInftyNorm_le

Plain-language statement

ℓ∞ subtraction bound. The ℓ∞ norm of a difference of two vectors, each within bound, is within subLInftyNormBound bound = 2·bound.

Exact Lean statement

theorem sub_lInftyNorm_le {cols : ℕ} (v w : PolyVec (Rq Φ) cols) {bound : ℕ}
    (hv : vecLInftyNorm Φ v ≤ bound) (hw : vecLInftyNorm Φ w ≤ bound) :
    vecLInftyNorm Φ (v - w) ≤ subLInftyNormBound bound

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
theorem sub_lInftyNorm_le {cols : } (v w : PolyVec (Rq Φ) cols) {bound : }    (hv : vecLInftyNorm Φ v  bound) (hw : vecLInftyNorm Φ w  bound) :    vecLInftyNorm Φ (v - w)  subLInftyNormBound bound := by  have hstep : vecLInftyNorm Φ (v - w)  vecLInftyNorm Φ v + vecLInftyNorm Φ w := by    unfold vecLInftyNorm    refine Finset.sup_le (fun i _ => ?_)    simp only [Pi.sub_apply]    calc Rq.lInftyNorm Φ (v i - w i)         Rq.lInftyNorm Φ (v i) + Rq.lInftyNorm Φ (w i) := Rq.lInftyNorm_sub_le Φ _ _      _  (Finset.univ : Finset (Fin cols)).sup (fun i => Rq.lInftyNorm Φ (v i))            + (Finset.univ : Finset (Fin cols)).sup (fun i => Rq.lInftyNorm Φ (w i)) :=          add_le_add            (Finset.le_sup (f := fun i => Rq.lInftyNorm Φ (v i)) (Finset.mem_univ i))            (Finset.le_sup (f := fun i => Rq.lInftyNorm Φ (w i)) (Finset.mem_univ i))  unfold subLInftyNormBound  omega
Project
ArkLib
License
Apache-2.0
Commit
fad5cbf80877
Source
ArkLib/Data/Lattices/CyclotomicRing/NormBounds/Basic.lean:226-241

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Project-declaredLean 4.31.0

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Plain-language statement

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Project-declaredLean 4.31.0

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Plain-language statement

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