Pull-back along surjective local analytic isomorphisms: empty centres and injectivity #
A good blow-up sequence functor should commute with smooth surjections [Kol07, 34.1]: the pull-back
along a surjective local analytic isomorphism of a list without empty centres has none (the centres
are preimages of nonempty sets under surjective lifts, surjective_blowUpLift), so eraseEmpty
changes nothing. The uniqueness of [Kol07, Proposition 37] (g^* B̄'(X) = B(X') = g^* B̄(X) forces
B̄'(X) = B̄(X), by [Kol07, Definition 30, 30.1]): pull-back along a surjective local analytic
isomorphism is injective on lists of centres (the centres are recovered as images, and the lifts
are again surjective).
[Kol07, Definition 30, 30.1]: the lift of a surjective local analytic isomorphism is surjective
(surjective_blowUpLift).
The pull-back along a surjective local analytic isomorphism of a list without empty centres has no empty centre.
[Kol07, 34.1] (eraseEmpty_pullback_of_surjective): deleting the
empty blow-ups of the pull-back along a surjective local analytic isomorphism changes nothing.
[Kol07, Proposition 37]: pull-back along a surjective local analytic isomorphism is injective on lists of centres.