Lemma 102 in the compatible-family form: the construction #
The functor BD_{n,m,j} of [Kol07, Lemma 102] is built in BD.lean from the marked
order-reduction functor BMO_{n-1,m} one dimension down: blow up the union Z_{-1} of the
components of E^j inside cosupp(I, m), restrict the weak transform I_0 and the boundary
E - E^j to the transform S_0 of E^j, apply the input functor to the restricted triple and push
the result forward, BD_{n,m,j}(X, I, E) := τ_* BMO_{n-1,m}(S, I_0|_S, m, E_S) ∘ π_{-1}. This
module
repeats the construction with the input in the compatible-family form: inp : BMOanFam 𝕜 (n - 1) s
(Functor/Family.lean), whose values are finite blow-up sequences on the relatively compact open
subsets, compatible under inclusion ([Wlo09, Theorem 2.0.3 (1), (4)]; the remark after
[BM97, Theorem 1.6] on locally finite sequences), in place of the structure BMOanData. The
constructions of BD.lean on the whole manifold are reused: the centre Z_{-1} and its blowing-up
π_{-1} (BD.Zminus1, BDan.piMinusOne), the transform S_0 = π_{-1}^{-1}(E^j)
(BDan.transformS), the restricted triple (S_0, I_0|_{S_0}, E_S) (BDan.restrictedTriple).
isCompact_closure_preimageOpens_of_isProperMap— the preimage of a relatively compact open under a proper analytic map is relatively compact.BDan.piOpenOf,BDan.isCompact_closure_piOpenOf— the preimageπ^{-1}(U)of an openUunder the blowing-up of a closed hypersurfaceZ, relatively compact whenUis (the blowing-up is proper);BDan.piOpenatZ = Z_{-1}.BDan.liftInclOf,BDan.isLocalDiffeomorph_liftInclOf— the lift of the inclusionU ⊆ Mto the blowing-up ofZ ∩ U, corestricted ontoπ^{-1}(U): a local analytic isomorphism onto that open, since the restriction of a blowing-up over an open is the blowing-up of the restricted centre;BDan.liftInclatZ = Z_{-1}.BDan.coreFamOn T s j inp hT U hU— the core on the relatively compact openU, for a triple whose ideal sheaf is D-balanced: the blowing-up ofZ_{-1} ∩ U, followed by the value of the input family on the restricted triple read at the trace ofπ_{-1}^{-1}(U)onS_0, pushed forward to the openπ_{-1}^{-1}(U)of the blown-up manifold ([Kol07, Definition 30 (3)]) and pulled back along the corestricted lift of the inclusion, with empty blow-ups deleted ([Kol07, 32]).BDanFam m inp T hT j U hU— the value ofBD_{n,m,j}onUfor a triple of the classBOClass m: the core at the marks = tuningParam mapplied to the tuned triple(M, W_s(𝓘), E)(Step 1 of Kollár's proof, "by (101) … we assume thatIis D-balanced";Tuned.lean), the input being the marked family at the marks.
The clauses of Lemma 102 for these values (the order clause, clause (1), the commutation with local
analytic isomorphisms, the indifference to empty members, the value at an empty member) and the
compatibility under restriction are proved in BDFamClauses.lean, BDFamOrder.lean,
BDFamCompat.lean, BDFamIndiff.lean and BDFamComm.lean, and assembled into the compatible
family bdanFam and the data bdanFamDataOfInput : BDanFamData ψ₀ (tuningParam m) in
BOanFamOfInput.lean, the input of Steps 2.1 and 2.2 of the proof of Theorem 103 in this form.
The preimage of a relatively compact open under a proper analytic map is relatively compact: the closure of the preimage lies in the preimage of the closure, which is compact.
The preimage of an open and the corestricted lift over an arbitrary closed hypersurface #
The preimage π^{-1}(U) of an open under the blowing-up of a closed hypersurface Z (piOpen
at Z = Z_{-1}).
Equations
- Hironaka.Manifold.BDan.piOpenOf hZ U = Manifold.preimageOpens ⇑(Manifold.blowUpπ ψ₀ hZ) ⋯ U
Instances For
π^{-1}(U) is relatively compact when U is: the blowing-up is a proper map.
The lift of the inclusion U ⊆ M to the blowing-ups of Z (BlowUpSequence.liftStep) lands in
π^{-1}(U).
The lift of the inclusion U ⊆ M to the blowing-up of Z ∩ U, corestricted onto the open
π^{-1}(U) of the blowing-up of Z (liftIncl at Z = Z_{-1}). It is a local analytic
isomorphism onto that open (isLocalDiffeomorph_liftInclOf; surjective by surjective_liftIncl in
BDFamTransport.lean): the restriction of a blowing-up over an open is the blowing-up of the
restricted centre.
Equations
Instances For
The corestricted lift of the inclusion is a local analytic isomorphism.
The preimage π_{-1}^{-1}(U) of an open U of M in the blowing-up of Z_{-1}.
Equations
Instances For
The lift of the inclusion U ⊆ M to the blowing-up of Z_{-1} ∩ U, corestricted onto the open
π_{-1}^{-1}(U) of the blowing-up of Z_{-1} (liftInclOf at Z_{-1}).
Equations
Instances For
The core of the proof of [Kol07, Lemma 102] on a relatively compact open U, for a triple of
BOClass s with D-balanced ideal sheaf and the input BMO_{n-1,s} in the compatible-family form:
the blowing-up of Z_{-1} ∩ U, then the input family's value on the restricted triple
(S_0, I_0|_{S_0}, E_S) read at the trace of π_{-1}^{-1}(U) on S_0, pushed forward to the open
π_{-1}^{-1}(U) ([Kol07, Definition 30 (3)]; BlowUpSequence.pushforwardRestrict) and pulled back
along
the corestricted lift of the inclusion, with empty blow-ups deleted ([Kol07, 32]).
Equations
- One or more equations did not get rendered due to their size.
Instances For
The core on U has no empty centres ([Kol07, 32]): they are deleted.
The value of BD_{n,m,j} on a relatively compact open U ([Kol07, Lemma 102], in the
compatible-family form): for a triple of the class BOClass m, the core at the mark
s = tuningParam m applied to the tuned triple (M, W_s(𝓘), E) (the tuning that opens the proof of
Lemma 102, Tuned.lean), with the input BMO_{n-1,s} in the compatible-family form. The member
E^j is named
by its index j.
Equations
- Hironaka.Manifold.BDanFam m inp T hT j U hU = Hironaka.Manifold.BDan.coreFamOn (T.tuned m ⋯) (IsLocalRing.tuningParam m) j inp ⋯ U hU
Instances For
The value of BD_{n,m,j} on U has no empty centres ([Kol07, 32]).