Original ledger status
SEAM.EQUIV.RIGID.01
SEAM.EQUIV.RIGID.01
ROUTE B (THE RIGIDITY ROUTE) FOR THE ONE OPEN ARROW L2, CARRIED OUT (2026-06-22) -- it lands on a strikingly SIMPLE statement: the whole keystone reduces to ONE question, does the raw seam carry the golden ratio? [E] RIGIDITY CLOSES THE CRYSTALLOGRAPHIC PART: the order-4 clock on a genus-0 surface has a UNIQUE conformal normal form z -> i z (Nielsen realisation theorem / Kerckhoff + uniformisation, v180); Troyanov's prescribed-curvature theorem gives the UNIQUE flat metric on the four-marked sphere (the pillowcase, v284). So the mu4/pillowcase data are rigidly fixed -- this half needs no new input. [E] THE DOWNSTREAM IS A LATTICE IDENTITY: beyond the McKay graph (v219), the Conway-Sloane fact that the ring of icosians (the 120 unit icosians = 2I, with the golden-ratio quaternion norm) is, as a rank-8 Z-module, the E8 LATTICE itself -- so '2I -> E8' is an identity of lattices, the strongest possible downstream link. [E] THE SINGLE BRIDGE IS THE GOLDEN RATIO: the crystallographic restriction allows only rotation orders {1,2,3,4,6} -- the 5-fold is NON-crystallographic; the mu4 clock (order 4) is crystallographic, the icosahedral 2I (5-fold) is not, and phi = 2 cos(pi/5) is EXACTLY what extends one to the other (the quasicrystal scaling; 2I = <order-4, golden>, the 96 golden icosians carry phi). [O] THE KEYSTONE REDUCES TO ONE QUESTION: IF the raw seam carries phi, THEN mu4 + phi generate 2I, the icosian ring gives E8, rigidity fixes the rest, and L2 is closed -- so the ENTIRE keystone reduces to 'does the raw quasi-free seam carry the golden ratio phi (as the icosian/quasicrystal scaling)?', the simplest possible form of L2. [O] THE HONEST SUBTLETY: TFPT's phi currently appears on the E8-SIDE -- the subleading eigenvalue of the affine-E8 attractor (v312) and the icosahedral atom 2 cos(pi/5) (v313), both already referencing E8/the icosahedron; the raw-seam data checked so far (cusp weights {0,1/3,2/3}, recovery (2/3)^6, seed phi0=1/(6pi)+48c3^4) are rational/transcendental, NOT manifestly golden. So showing the RAW seam carries phi NON-circularly (before assuming E8) is the residual -- it IS L2 in its sharpest form. Route B reduces the keystone to 'is there a phi in the raw seam?'; it does not answer it.
Recorded status: Route B / reduction [E]/[O] (rigidity + the icosian-ring identity reduce L2 to one question: does the raw seam carry the golden ratio?; NOT closed)
Dependencies, status detail and source
Canonical status: [E] the rigidity reductions (Nielsen/Troyanov close the crystallographic mu4/pillowcase part), the icosian-ring lattice identity (E8 = icosians), the crystallographic role of phi (the 5-fold is non-crystallographic, phi bridges); [O] the single reduced arrow ('the raw seam carries the golden ratio'), with the honest flag that TFPT's phi is currently E8-side (potential circularity). Route B; closes nothing, reduces the keystone to one question.
Dependencies: SEAM.EQUIV.CLOSURE.01; v180; v284; v219; v312; v313
Scripts: v348_seam_rigidity_route.py
Location: origin_theory
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