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MathlibNt.AnalyticNumberTheory.Chen1973.Chen1973Lemma5SwitchedTripleSource

Chen 1973, Lemma 5: the actual switched triple source #

This file freezes the opening of Lemma 5 on pp. 116--119 of Chen's original scan. It keeps the actual von Mangoldt coefficient, Chen's finite Perron kernel Φ(x/(p₁p₂n)), and the reciprocal logarithmic weight. In particular it does not replace the source by an arbitrary coefficient sequence.

The analytic estimates in Lemmas 5--6 are not asserted here. The first layer is the exact finite bookkeeping used before those estimates: the prime-triple carrier, the Selberg-square expansion, the principal/nonprincipal partition, and the resulting M₁-M₃+M₄ identity.

A natural cutoff version of Chen's Q=∏_{2≤p<x^(1/4)}p. The relation to the real fourth root is carried separately, so the finite product never uses a fake real-indexed finset.

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    AnalyticNumberTheory.LargeSieve.chen1973Lemma5Q · compiled type and proof/definition references.

    An honest natural cutoff realizes the source's strict real fourth-root cutoff when these membership predicates agree.

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      AnalyticNumberTheory.LargeSieve.Chen1973FourthRootCutoff · compiled type and proof/definition references.

      theorem AnalyticNumberTheory.LargeSieve.mem_chen1973Lemma5QCarrier_iff {x z4 p : ℕ} (hz : Chen1973FourthRootCutoff x z4) (hp : Nat.Prime p) :
      p ∈ {q ∈ Finset.range z4 | 2 ≤ q ∧ Nat.Prime q} ↔ 2 ≤ p ∧ ↑p < ↑x ^ (1 / 4)

      Under the explicit cutoff bridge, membership in the finite Q carrier is exactly the source condition 2 ≤ p < x^(1/4).

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      AnalyticNumberTheory.LargeSieve.mem_chen1973Lemma5QCarrier_iff · compiled type and proof/definition references.

      The finite pair carrier printed at the start of Lemma 5: x^(1/10)<p₁≤x^(1/3)<p₂≤(x/p₁)^(1/2).

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        AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrimePairs · compiled type and proof/definition references.

        The actual finite triple carrier counted by Ω, before the coprimality sieve is imposed.

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          AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrimeTriples · compiled type and proof/definition references.

          Chen's Ω: prime triples in the printed carrier for which (x-p₁p₂p₃,Q)=1.

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            AnalyticNumberTheory.LargeSieve.chen1973Lemma5OmegaCarrier · compiled type and proof/definition references.

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            AnalyticNumberTheory.LargeSieve.chen1973Lemma5Omega · compiled type and proof/definition references.

            Literal membership conditions for the finite Ω carrier.

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            AnalyticNumberTheory.LargeSieve.mem_chen1973Lemma5OmegaCarrier_iff · compiled type and proof/definition references.

            Chen p. 115: f(k)=φ(k)∏_{p∣k}(p-2)/(p-1).

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              AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergF · compiled type and proof/definition references.

              The normalized finite denominator in Chen's literal Selberg coefficient.

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                AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergDenominator · compiled type and proof/definition references.

                The actual coefficient λ_d defined immediately before Lemma 5 (p. 115). R is the honest natural version of x^(1/4-ε/2).

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                  AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergLambda · compiled type and proof/definition references.

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                  AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergLambda_one · compiled type and proof/definition references.

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                  AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergLambda_eq_zero_of_cutoff · compiled type and proof/definition references.

                  The finite n≤x/(p₁p₂) carrier used after switching p₃ to Λ(n).

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                    AnalyticNumberTheory.LargeSieve.chen1973Lemma5NCarrier · compiled type and proof/definition references.

                    The literal source weight Λ(n) Φ(x/(p₁p₂n)) / log(x/(p₁p₂)). The value at a zero denominator is totalized by Lean's field operations; on the prime-pair carrier the later analytic development proves the required positivity separately.

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                      AnalyticNumberTheory.LargeSieve.chen1973Lemma5SmoothedWeight · compiled type and proof/definition references.

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                      AnalyticNumberTheory.LargeSieve.chen1973Lemma5M · compiled type and proof/definition references.

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                      AnalyticNumberTheory.LargeSieve.chen1973Lemma5DivisorCarrier · compiled type and proof/definition references.

                      The finite Selberg divisor sum appearing inside the square in (5).

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                        AnalyticNumberTheory.LargeSieve.chen1973Lemma5DivisorSum · compiled type and proof/definition references.

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                        AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergSquare · compiled type and proof/definition references.

                        The literal switched Λ·Φ/log mass on the Ω carrier. Keeping this quantity separate avoids silently replacing Chen's smoothed source by a bare cardinality.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5OmegaSmoothed · compiled type and proof/definition references.

                          theorem AnalyticNumberTheory.LargeSieve.chen1973Lemma5SmoothedWeight_nonneg {x : ℕ} (hx : 1 < x) {pp : ℕ × ℕ} {n : ℕ} (hlog : 0 ≤ Real.log (↑x / (↑pp.1 * ↑pp.2))) :

                          The source weight is nonnegative once its (printed) logarithmic denominator is known to be nonnegative. The nonnegativity of Λ and of Chen's finite Perron kernel are discharged internally.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5SmoothedWeight_nonneg · compiled type and proof/definition references.

                          The finite product defining Q is nonzero.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5Q_ne_zero · compiled type and proof/definition references.

                          theorem AnalyticNumberTheory.LargeSieve.chen1973Lemma5DivisorSum_eq_one_of_coprime {x z4 : ℕ} {lambda : ℕ → ℝ} (hlambda : lambda 1 = 1) {pp : ℕ × ℕ} {n : ℕ} (hcop : (x - pp.1 * pp.2 * n).Coprime (chen1973Lemma5Q z4)) :
                          chen1973Lemma5DivisorSum x z4 lambda pp n = 1

                          On an Ω residue, every divisor of Q which divides the residue is one; therefore a Selberg divisor sum normalized by λ₁=1 is exactly one.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5DivisorSum_eq_one_of_coprime · compiled type and proof/definition references.

                          Exact reindexing of the smoothed Ω source into the switched pair/n coordinates used by the Selberg square.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5OmegaSmoothed_eq_switched · compiled type and proof/definition references.

                          The actual smoothed Ω mass is bounded by the actual Selberg square. The only hypotheses are λ₁=1 and nonnegativity of the source weights; the latter is supplied by chen1973Lemma5SmoothedWeight_nonneg from the genuine Λ·Φ/log definition.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5OmegaSmoothed_le_SelbergSquare · compiled type and proof/definition references.

                          A separate, honest cardinal bridge. It applies when the retained smoothed weight is pointwise at least one; this condition is deliberately explicit and is not conflated with mere nonnegativity of the Perron weight.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5Omega_le_OmegaSmoothed · compiled type and proof/definition references.

                          theorem AnalyticNumberTheory.LargeSieve.chen1973Lemma5Omega_le_SelbergSquare {x z4 : ℕ} {lambda : ℕ → ℝ} (hlambda : lambda 1 = 1) (hw0 : ∀ pp ∈ chen1973Lemma5PrimePairs x, ∀ n ∈ chen1973Lemma5NCarrier x pp, 0 ≤ chen1973Lemma5SmoothedWeight x pp n) (hw1 : ∀ t ∈ chen1973Lemma5OmegaCarrier x z4, 1 ≤ chen1973Lemma5SmoothedWeight x t.1 t.2) :

                          Cardinal form of the Ω--Selberg-square bridge, with the genuinely stronger pointwise lower bound isolated from the internally proved sign condition.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5Omega_le_SelbergSquare · compiled type and proof/definition references.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5ProgressionTerm · compiled type and proof/definition references.

                          Expansion of Chen's Selberg square into the two divisor variables.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergSquare_eq_expanded · compiled type and proof/definition references.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrincipalAll · compiled type and proof/definition references.

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                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrincipalGood · compiled type and proof/definition references.

                          The complementary principal contribution (p₁p₂n,d₁d₂)>1, source M₃.

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                            AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrincipalBad · compiled type and proof/definition references.

                            Pure finite partition of the principal sum into good and bad gcd lanes.

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                            AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrincipalAll_eq_good_add_bad · compiled type and proof/definition references.

                            noncomputable def AnalyticNumberTheory.LargeSieve.chen1973Lemma5M1 (x z4 : ℕ) (lambda : ℕ → ℝ) :

                            Source M₁: the unrestricted principal-character main term.

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                              AnalyticNumberTheory.LargeSieve.chen1973Lemma5M1 · compiled type and proof/definition references.

                              noncomputable def AnalyticNumberTheory.LargeSieve.chen1973Lemma5M3 (x z4 : ℕ) (lambda : ℕ → ℝ) :

                              Source M₃: the non-coprime correction removed from M₁.

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                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5M3 · compiled type and proof/definition references.

                                noncomputable def AnalyticNumberTheory.LargeSieve.chen1973Lemma5M4 (x z4 : ℕ) (lambda : ℕ → ℝ) :

                                Source M₄ at the finite pre-contour level: the exact progression remainder after subtracting the coprime principal-character term.

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                                  AnalyticNumberTheory.LargeSieve.chen1973Lemma5M4 · compiled type and proof/definition references.

                                  The actual twisted switched source at modulus q; the coefficient remains literally Λ(n) Φ(x/(p₁p₂n)) / log(x/(p₁p₂)).

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                                    AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrimitiveTwist · compiled type and proof/definition references.

                                    theorem AnalyticNumberTheory.LargeSieve.chen1973Lemma5_character_orthogonality {q x a : ℕ} [NeZero q] (hxq : x.Coprime q) :
                                    ∑ χ : DirichletCharacter ℂ q, star (χ ↑x) * χ ↑a = if ↑x = ↑a then ↑q.totient else 0

                                    The pointwise Dirichlet-character orthogonality relation needed to turn a progression condition into a character sum. Unlike a black-box source premise, this finite step is proved directly from Mathlib's orthogonality API.

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                                    AnalyticNumberTheory.LargeSieve.chen1973Lemma5_character_orthogonality · compiled type and proof/definition references.

                                    The old one-conductor signed ledger. It is useful as the inner character majorant, but it is not Chen's p. 117--119 source M₂: that source still has an outer squarefree d-sum and the restriction (p₁p₂,d)=1.

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                                      AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2Signed · compiled type and proof/definition references.

                                      Compatibility name for the old one-conductor norm ledger. This is only an inner majorant (the shape later denoted N_m after inserting a prime-pair filter), not the source M₂ of Lemma 5. The source-faithful object is chen1973Lemma5M2Source below.

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                                        AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2InnerMajorant · compiled type and proof/definition references.

                                        Legacy API retained for downstream files. Semantically this is the one-conductor inner majorant, not source M₂.

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                                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2 · compiled type and proof/definition references.

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                                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2OuterDivisors · compiled type and proof/definition references.

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                                          AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2OuterWeight · compiled type and proof/definition references.

                                          The literal primitive twist after retaining the source condition (p₁p₂,d)=1. The character conductor is the independent inner variable l.

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                                            AnalyticNumberTheory.LargeSieve.chen1973Lemma5PrimitiveTwistCoprime · compiled type and proof/definition references.

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                                            AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2SourceInner · compiled type and proof/definition references.

                                            Source-faithful M₂ on pp. 117--119: first the outer d weight, then the independent inner conductor l primitive-character sum, with (p₁p₂,d)=1 inside the prime-pair carrier.

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                                              AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2Source · compiled type and proof/definition references.

                                              Signed pre-norm form of the same two-layer source. This is the exact finite target for the Selberg/character expansion of the actual M₄ remainder.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2SourceSigned · compiled type and proof/definition references.

                                                The old one-conductor real-part ledger is bounded by its norm ledger.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2Signed_le_M2 · compiled type and proof/definition references.

                                                Taking norms conductor-by-conductor bounds the signed two-layer source.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5M2SourceSigned_le_source · compiled type and proof/definition references.

                                                Finite M₄ ≤ M₂ connector with the correct source object. The premise is exactly the still-separate Selberg-coefficient/imprimitive-character expansion; the norm step itself is proved here.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5M4_le_M2_of_conductor_grouping · compiled type and proof/definition references.

                                                The preceding connector specialized to Chen's actual p. 115 Selberg coefficient, making the link to the concrete M₄ remainder explicit.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5ActualM4_le_M2Source_of_character_expansion · compiled type and proof/definition references.

                                                Exact finite M₁-M₃+M₄ decomposition of the expanded Selberg square.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5_expanded_eq_M1_sub_M3_add_M4 · compiled type and proof/definition references.

                                                Equation (5), now as a kernel-checked finite identity.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5SelbergSquare_eq_M1_sub_M3_add_M4 · compiled type and proof/definition references.

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                                                AnalyticNumberTheory.LargeSieve.chen1973Lemma5ActualSelbergSquare_eq_M1_sub_M3_add_M4 · compiled type and proof/definition references.