An explicit noninduced Langlands quotient with vanishing unitary periods

This attributed mathematical note gives a complete checkable proof for F=Q3 and its unramified quadratic extension E: the GL15 Langlands quotient with segments [4,6],[2,5],[3,3],[1,4],[0,2] is tau invariant, is not an entire proper parabolic induction, and has no unitary-stabilizer period for either Hermitian isometry class. The total is zero instead of two in the historical OWR14/2011 Conjecture4 k=1 smooth-complex p-adic interpretation. The same example contradicts FLO Conjecture6.12 and the unrestricted local unitary Jacquet converse; it does not contradict generic or tempered positive results. FLO supplies the complete period bases, normalization, functional equations and adjacent-label exclusion. JPSS supplies segment L-factors; Lapid-Minguez supplies classification, ladder-side matching, involution and prior kernel transport. Gurevich-Ma-Mitra and Mitra-Offen-Sayag supply earlier imprimitive negative-distinction and quotient-descent antecedents for different subgroups. Beuzart-Plessis and Lu-Matringe receive credit for established generic/tempered results; Sharma for a different five-segment combinatorial comparison. Historical priority and every substantive overlap comparison with Luo-Zha, A Remark on Bernstein-Zelevinsky Classification for General Linear Groups, DOI10.1007/s11464-025-0256-0, are UNKNOWN. Their complete body was unavailable and uninspected. Their documented earlier kernel-generation counterexample claim is credited. This note may overlap or be superseded by it. No worldwide novelty, firstness, current-open-status or separate kernel-generation disproof claim is made. AI tools were used extensively in construction, source comparison, adversarial checks, computations and writing. This is unrefereed, without external human peer review, journal acceptance or proof-assistant certification. The standard-library exact verification kit corroborates finite identities and conditions; the written argument and published theorem dependencies establish the representation-theoretic conclusion. Authored text and code are CC BY4.0.