# T707 build research Checked sources (archived HTML paths and SHA-256 in source-archives.json): - https://arxiv.org/html/math/0011254v1 §1.1 (1.4), §1.2 (1.14): g_N=sum mu(n)/n and B_N=sum mu(n)rho_n-Ng_Nrho_N. Target is -chi, ordinary fractional parts, L^2((0,infinity),dx). Equation (1.18) calls the untapered sum S_n; (1.19) calls the distinct dual sum F_n. - https://arxiv.org/html/math/0202141v2 §1 (1.1) instead calls the untapered sum F_n. This table translates that notation explicitly. - https://arxiv.org/html/math/0306251v1 §4 and §9 Propositions 87/89: signed V(p,q), V(p,1)=0, A(1)=log(2pi)-gamma, rational A(p/q) formula. Checked live: one authenticated catalogue pass includes drafts; no duplicate. T639 is the signed cotangent ingredient, T640 the kernel, T641 the unrestricted minimum (N=1,...,30), T642 the logarithmic taper (N=2,...,30). T706 is the untapered baseline, currently offered for review. No sibling value is an input or independent evidence. Those live metadata snapshots are retained locally. The shared family proposal's sole direct wanted link is contributes to #273, which was read and supports named constructive residual norms; #313 is the proposal. No claim of completing #273. The first draft message preserves both. screen.py already_here/already_asked searches were run for Baez Duarte and Nyman Beurling. Correct api/lookup checks for 1, 1-log2 and the N=3 sample found only generic exact-one or different-context coincidences; no N=3 match. The first direct lookup attempt mistakenly used expression= and was rejected; lookup-correct.json preserves the successful cheap lookups. This correction occurred immediately after the title-only claim, before filling or long work. Both tag pages lack Nyman-Beurling criterion. Existing tags number theory and functional analysis are used; the new family tag is only recommended for T639–T642 and the four proposed constructions, without changing old tables. Checked deductions: B_N=0 for x>1 and B_N=-1 for 1/N