M28b reduces the full Hypertriad of M28a (ten-member rhombus at R = 4) to a working Triad that mirrors the rank‑3 structure while preserving the essential geometry. The reduction is conceptual, not eliminative: the Hypertriad remains the ambient structure, but a minimal triangle is selected for clarity and operability. The resulting R = 4 Triad is Ctet, TMultB, HCt. It corresponds structurally to the rank‑3 Triad Cpow, Apow, aᵇ. Each vertex arises from a distinct structural lesson of M28a: Ctet = HC genuine symmetric operation TMultB = TC shelf (slog arithmetic) HCt = asymmetric a-ONS (chirality midpoint) The reduction is guided by three structural identifications: HCt plays the role of the asymmetric member (analog of aᵇ) TMultB represents the TC shelf as the unique multiplicative structure Ctet remains the HC symmetric anchor Thus the triangle preserves the HC / SC (role replaced by TC) / asymmetric pattern of the Triad. The TC operations retain their defining structure: TMultB (a, b) = tetB (slogB (a) * slogB (b) ). The key conceptual move is that the two-étage Hypertriad is collapsed into a single effective shelf (TC), while the chirality sector is absorbed into a single asymmetric representative (HCt). This produces an operational chart in which: the full Hypertriad = ambient geometry the R=4 Triad = usable coordinate system The reduction enables direct comparison across ranks: R = 3: Cpow, Apow, aᵇ R = 4: Ctet, TMultB, HCt. M28b therefore does not add new operations; it provides a canonical representation of R = 4 that makes subsequent constructions (notably the ISHE bridge at R = 3. 5) structurally transparent.
Paweł Łukasz Garycki (Fri,) studied this question.