The Resonance Line Splits into Three Rees Shifts and One Incidence Shift
For the exact odd resonant coefficient of Entries 517--518, remove the
common Cartier factor u. The remaining weighted monomial is
On the u-chart of Bl_(u,a^2), where a^2=ut,
After removing the three exceptional powers u^3, the normalized generator
is
On the a^2-chart the corresponding normalization uses the odd frame a.
On the overlap, the Rees part of the transition is therefore t^3. The
remaining factor b+1 is not an additional blowup-chart transition: it is
the source incidence line carried by L_1|_(u=0).
Restricting to the Cartier section
gives the comparison coefficient
and hence
Thus the relative exceptional line is canonically typed as three
tautological weighted-Rees shifts tensor one incidence shift. The Čech
transition and endpoint divisor are compatible but distinct data: t^3
glues the weighted charts, while b+1 supplies the asymmetric endpoint
order.
This verifies the line-bundle coherence required by Entries 455--456. It does not yet construct the boundary differential or its nullhomotopy; that is the remaining datum needed to place the odd resonance in the relative homotopy fiber.