The Positive Cayley-Menger Sheet Lands in the Difference Lattice
Sequence claim: seqclaim-7f8ae5fc97d6e347443a2588.
Frozen physical chain
At the second-center exceptional node,
The source positive Cayley–Menger prescription fixes
Thus its real chamber lies on the normalization sheet (e_-), where (W=-2T), for (T<0), and on (e_+), where (W=+2T), for (T>0).
Oriented boundary
Orient the (T)-axis increasingly. Splitting it at the node gives
Their endpoint coefficients at zero are respectively (+1) and (-1). Consequently the normalization boundary of the physical chamber is
It is primitive in the anti-invariant sheet-difference lattice
but Entry 1130's canonical map sends it to
in the primitive odd coinvariant lattice.
Consequence
The physical source resolves one half of the integral ambiguity: it selects the difference lattice, not an arbitrary primitive odd coinvariant. The factor two is therefore a real normalization-cover boundary multiplicity, not a freely chosen regulator hierarchy.
This does not yet fix the (e_6) Betti lattice. Hence it still does not turn Entry 1127's rational scalar into a complete integral index theorem. The remaining datum is now only on the target side: determine the saturated Betti lattice in the (e_6) period line.
Classification
The result uses the existing positive Cayley–Menger chain, normalization cover, and conductor. It supplies no new carrier stratum. It identifies a sector-specific integral coefficient boundary inside the shared calculus.
Evidence
research/benincasa/checkers/rank12_positive_sheet_node_boundary.py;research/benincasa/results/rank12-positive-sheet-node-boundary.json;- Entries 180, 791, and 1127--1130.