3760 — The Sheet Pair Supplies the Coherence Carrier but Not Selective Loop Authority
Endogenous part of the completion
The pre-projection magnetic sheet packet ((A,B)) is an orbitwise two-dimensional coherence carrier. Reflection exchanges its coordinates, and
is the canonical Hadamard atlas. The source therefore supplies the minimal carrier and complementary parity ports found abstractly in Entry 3757.
Remaining obstruction
The metaplectic central loop acts diagonally as (-I_2). It is reflection-equivariant but produces only a global sign. A one-sheet sign
would convert an even sheet vector into an odd one, but does not commute with sheet exchange. It is not generated by the established reflection-equivariant source algebra.
The missing constructor is consequently reflection-framed sheet addressability: a globally coherent sheet framing together with authority for the central loop to act on one sheet while its partner remains fixed. Either part alone is insufficient.
Evidence
research/strominger/the-sheet-pair-supplies-the-coherence-carrier-but-not-selective-loop-authority.md;research/strominger/checkers/sheet_pair_coherence_carrier_selective_action_no_go_checks.py;research/strominger/results/sheet_pair_coherence_carrier_selective_action_no_go_checks.json.
The exact checker passes 10 of 10 gates. Checker SHA-256:
bd59e64f53c02e8ba6cf803bcc0dfd1b0e7da9992fe0095743eb6bab5f59294d.
Allocator claim: seqclaim-a7a43370abdf702a4cf5063b.