The core of Step 2.2: CP1 along the raw output of Lemma 102 #
[Kol07, Lemma 102] on a triple (X, I, E) with a member H = E^j of maximal contact for (I, 1)
blows up Z_{-1}, the components of H along which I has order ≥ 1, and pushes forward the
inductive run on the strict transform of H. For the reduced component c̄ ⊆ V(I) ⊆ H of a
generic point η of V(I) off the other members, the statement CP1 of the embedded
desingularization (Hironaka.Resolution.Algebraic.Wlo05.EmbeddedChainRelative) along this raw
output for (I, E − E^j) follows from CP1 for the inductive run (the hypothesis hcp1, the stage
below):
- Case A:
Z_{-1}containsc̃. Thenc̄is a component ofH(mem_genericPoints_of_Zminus1_le), a smooth divisor with the stalks ofH(isSmoothDivisor_vanishingIdeal_closure_of_mem_genericPoints,stalkIdeal_vanishingIdeal_closure_eq_of_isSmoothDivisor), andchainRelativeAt_of_le_isSmoothDivisor(Hironaka.Resolution.Algebraic.Wlo05.EmbeddedChainCaseA) gives the chain form at the first stage; later stages are excluded by the stop rule. - Case B: the first blow-up does not contain
c̃. OnHthe run iscons (Z_{-1}|_H) (B …), its first blow-up does not contain the level component (cp1For_cons_of_not_centerContains), andhcp1on the restricted triple, whose ideal and boundary are exactly the level data after the first blow-up, gives CP1 for the tail;cp1For_pushforward(Hironaka.Resolution.Algebraic.Wlo05.EmbeddedCP1Pushforward) carries it toX.
This is Step 2.2 of the proof of [Kol07, Theorem 103] read for CP1; the argument is not in the
literature. Used in Hironaka.Resolution.Algebraic.Wlo05.EmbeddedCP1Step22.
The core of Step 2.2 (the proof of [Kol07, Lemma 102] read for CP1): for a triple
(X, I, E) with max-ord I = m = 1, a member H = E^j that is a smooth hypersurface with
H ⊆ V(I), and a generic point η of V(I) off the other members with I_η its reduced ideal,
the raw output of Lemma 102 satisfies CP1 for (I, E − E^j) at η, given CP1 for the inductive
run B at the mark 1.