The Moving-Seam Conservation Law Is Maximally Blind on the Zero-State
The source-native seam extension is the moving-cut decomposition
Its exact flow is T'=-r, B'=r, with r=f(L)e^{sL}. Hence the common mode
is conserved. But at an Evans zero the entire seam trajectory satisfies
B_s=-T_s: it lies in the anti-diagonal kernel of the conserved sum, and its
tangent lies there as well.
The missing information is the relative channel
On a zero-state C_s=0 while D_s is generally nonzero. Consequently the
first cross-tower coherence cell preserves exactly the scalar quotient that is
blind to zero-state motion. A higher comparison channel sensitive to D_s is
mandatory. The next exact test is Fourier--Tate sewing on (C_s,D_s) and
nondegeneracy of its bilinear form on C_s=0.
Research packet:
research/grothendieck/the-moving-seam-conservation-law-is-maximally-blind-on-the-zero-state.md
Exact checker:
research/grothendieck/checkers/check_moving_seam_zero_state_blindness.py
The checker passes 7/7 exact tests.