Compatible families of blow-up sequences and the family functors #
Włodarczyk's resolution of an analytic space is a compatible family: a finite blow-up sequence
over every relatively compact open subset, the sequences over U ⊆ V compatible under restriction
up to empty blow-ups [Wlo09, Theorem 2.0.3, (1) and (4)], the notion of extension being
[Wlo09, Definition 3.2.6]; the vocabulary of the main theorems has the corresponding
AnalyticManifold.ExtensionCompatibleFamily. Accordingly the analytic order-reduction
functors have, beside their finite form on triples, a family form: the value on a triple is a
finite CenterList on every relatively compact open U ⊆ M, with no empty blow-ups
([Kol07, 32]), compatible under restriction up to empty blow-ups.
This file provides the general tool AnalyticMap.restrictMap (the restriction of an analytic map
to a pair of opens, with restrictLE, the open inclusion U ⊆ V, as its instance at the
identity) and its properties (image opens, compact closure of images, local isomorphism and
surjectivity of restrictions); CompatibleFamily; the family functor AnalyticFamilyFunctor with
its commutation ([Kol07, 34.1]) and indifference predicates; the records BOanFam and BMOanFam
of the order-reduction functors in family form; and the per-open bridge
AnalyticBlowUpSequenceAssignment.toFamily from a finite functor to a family functor.
The general restriction of an analytic map to a pair of opens #
The restriction of an analytic map
g : N → M to opens U' ⊆ N, V ⊆ M with g '' U' ⊆ V, as an analytic map
N.restrict U' → M.restrict V. Its instance at g = id is the open inclusion restrictLE, and it
is also the restriction g|_{U'} of a cover map and of a local isomorphism in the commutation
predicates of the family functors: one constructor for all three.
Equations
Instances For
The open inclusion M.restrict U → M.restrict V for U ≤ V, the id-instance of
restrictMap.
Equations
- M.restrictLE hUV = ⟨TopologicalSpace.Opens.inclusion hUV, ⋯⟩
Instances For
The compatible family of finite blow-up sequences #
The value of an
order-reduction functor on a triple T — a finite CenterList on every relatively compact open
U, with no empty blow-ups, compatible under restriction U ≤ V up to empty blow-ups: the value
on U is the pull-back of the value on V along the inclusion with its empty centres deleted
(one-sided, seqOn having no empty centres). The analogue of the vocabulary's
AnalyticManifold.ExtensionCompatibleFamily.
- seqOn (U : TopologicalSpace.Opens M.carrier) : IsCompact (closure ↑U) → AnalyticManifold.BlowUpSequence ψ₀ (M.restrict U)
The finite blow-up sequence over each relatively compact open.
- noEmptyCenters (U : TopologicalSpace.Opens M.carrier) (hU : IsCompact (closure ↑U)) : (self.seqOn U hU).NoEmptyCenters
No empty centres ([Kol07, 32], per open).
- compat (U V : TopologicalSpace.Opens M.carrier) (hU : IsCompact (closure ↑U)) (hV : IsCompact (closure ↑V)) (hUV : U ≤ V) : self.seqOn U hU = ((self.seqOn V hV).pullback (M.restrictLE hUV) ⋯).eraseEmpty
Compatibility under restriction, up to empty blow-ups ([Wlo09, Theorem 2.0.3, (4)]; Wlo09, Definition 3.2.6).
Instances For
The trivial family — the empty CenterList on every open — is a
CompatibleFamily for every triple (compatibility by pullback_nil and eraseEmpty_nil). The
value of the trivial family functor nilFamilyFunctor.
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- One or more equations did not get rendered due to their size.
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On a manifold whose whole space is relatively compact (in particular a
compact M), a CompatibleFamily is determined by its value at ⊤ — every open lies below ⊤, so
compat reads every seqOn U hU off seqOn ⊤. The finite and family layers agree there.
More tools for restrictMap: the image open, its compact closure, local #
diffeomorphism, surjectivity and range
The image g '' U' of a relatively compact open under a local analytic
isomorphism g, as an open subset of the codomain (g is an open map,
IsLocalDiffeomorph.isOpenMap). The codomain open onto which g|_{U'} is surjective in
CommutesWithLocalIsos.
Equations
- Hironaka.Manifold.AnalyticMap.imageOpens g hg U' = { carrier := ⇑g '' ↑U', is_open' := ⋯ }
Instances For
The closure of the image of a relatively compact open under g is compact —
closure (g '' U') ⊆ g '' closure U', a compact (hence closed, the codomain is Hausdorff) set, and
a closed subset of a compact set is compact. Makes g.imageOpens hg U' a valid index of seqOn.
g|_{U'} : N.restrict U' → M.restrict V is a local analytic isomorphism when
g is — it factors as (M.inclusion V)⁻¹ ∘ g ∘ N.inclusion U', a composite of local
diffeomorphisms (IsLocalDiffeomorphAt.comp; inclusionInv is the local inverse of the open
inclusion on V). Needed to pull a family back along g|_{U'}.
g|_{U'} is surjective onto the image open (g '' U' = V). This is why the
two bullets of [Kol07, 34.1] collapse to one clause per open: g|_{U'} is always onto its image.
The range of g|_{U'} in M.restrict V is the preimage of the image g '' U'
under the inclusion of V.
The range of the open inclusion restrictLE in M.restrict V is the preimage
of U under the inclusion of V.
The open inclusion restrictLE is an analytic open embedding (a local analytic
isomorphism that is injective) — the datum CommutesWithOpenEmbeddings reads in the bridge.
If g is a coproduct of open
embeddings, so is g|_{U'} — the clopen decomposition of N pulls back to one of N.restrict U',
g injective on each piece.
The open inclusion restrictLE is the g = id instance of
restrictMap (rfl), so that the two constructors are interchangeable.
The family functor on a class and its per-open commutation predicates #
A
family order-reduction functor on a class Dom — a compatible family of finite blow-up
sequences for every triple of the class. The single field is fam; commutation and indifference
are predicates on it, consumed by the records BOanFam/BMOanFam as
fields.
The compatible family assigned to each triple of the class.
Instances For
B commutes with local analytic isomorphisms — for a local analytic
isomorphism g : N → M with T' carrying the pull-back data of T (both in Dom) and every
relatively compact open U' ⊆ N, the value on U' is the pull-back along g|_{U'} : U' → g(U')
(always onto its image, so the two bullets of 34.1 unite) of the value on the relatively compact
open g(U'), with empty blow-ups erased.
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- One or more equations did not get rendered due to their size.
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Deleting empty
boundary members changes no seqOn U hU.
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- One or more equations did not get rendered due to their size.
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The family form of the order-reduction functor
BO_{n,m} — a family functor on the class BOClass m at the standard model with four
clauses read per relatively compact open on the restricted triple
T.pullback (M.inclusion U) (isLocalDiffeomorph_inclusion M U). It lives in Type (u+1).
The clauses of [Kol07, Theorem 103, (3)] and [Kol07, 108] are not fields.
- functor : AnalyticFamilyFunctor (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) fun {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} => Manifold.AnalyticTriple.BOClass m
The family functor
BO_{n,m}on the order-reduction class at the standard model𝕜ⁿ. - isOfOrderGe {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} (T : Manifold.AnalyticTriple (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) M) (hT : Manifold.AnalyticTriple.BOClass m T) (U : TopologicalSpace.Opens M.carrier) (hU : IsCompact (closure ↑U)) : ((self.functor.fam T hT).seqOn U hU).toSuccession.IsOfOrderGe (T.pullback (M.inclusion U) ⋯).I m (T.pullback (M.inclusion U) ⋯).F.idealSheaf
[Kol07, Definition 66] (2′)–(4′), per open: the value on
Uis a smooth blow-up sequence of order≥ mstarting with the restricted(M, 𝓘, m, E). - ord_lt {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} (T : Manifold.AnalyticTriple (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) M) (hT : Manifold.AnalyticTriple.BOClass m T) (U : TopologicalSpace.Opens M.carrier) (hU : IsCompact (closure ↑U)) (x : (((self.functor.fam T hT).seqOn U hU).toSuccession.stage (Fin.last ((self.functor.fam T hT).seqOn U hU).toSuccession.length)).carrier) : Manifold.IdealSheaf.ord (((self.functor.fam T hT).seqOn U hU).toSuccession.markedTransformSeq (T.pullback (M.inclusion U) ⋯).I m (Fin.last ((self.functor.fam T hT).seqOn U hU).toSuccession.length)) x < ↑m
Theorem 103 (1) ("
max-ord I_r < m"), pointwise per open: the marked transform at the last stage overUhas order< mat every point. - commutesWithLocalIsos : self.functor.CommutesWithLocalIsos
Theorem 103 (2): the functor commutes with local analytic isomorphisms.
- indifferentToEmptyMembers : self.functor.IndifferentToEmptyMembers
The functor is indifferent to empty boundary members.
Instances For
The family form of the marked
order-reduction functor BMO_{n,m} — a family functor on the class BMOClass m (no order
bound) at the standard model with the four BMOanData clauses read per relatively compact open on
the restricted triple. Type (u+1) as the finite record. The clauses of [Kol07, Theorem 107, (3)]
and [Kol07, 108] are not fields.
- functor : AnalyticFamilyFunctor (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) fun {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} => Manifold.AnalyticTriple.BMOClass m
The family functor
BMO_{n,m}on the marked class at the standard model𝕜ⁿ. - isOfOrderGe {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} (T : Manifold.AnalyticTriple (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) M) (hT : Manifold.AnalyticTriple.BMOClass m T) (U : TopologicalSpace.Opens M.carrier) (hU : IsCompact (closure ↑U)) : ((self.functor.fam T hT).seqOn U hU).toSuccession.IsOfOrderGe (T.pullback (M.inclusion U) ⋯).I m (T.pullback (M.inclusion U) ⋯).F.idealSheaf
[Kol07, Definition 66] (2′)–(4′), per open: the value on
Uis a smooth blow-up sequence of order≥ mstarting with the restricted(M, 𝓘, m, E). - ord_lt {M : AnalyticManifold 𝕜 (Fin n → 𝕜)} (T : Manifold.AnalyticTriple (ContinuousLinearEquiv.refl 𝕜 (Fin n → 𝕜)) M) (hT : Manifold.AnalyticTriple.BMOClass m T) (U : TopologicalSpace.Opens M.carrier) (hU : IsCompact (closure ↑U)) (x : (((self.functor.fam T hT).seqOn U hU).toSuccession.stage (Fin.last ((self.functor.fam T hT).seqOn U hU).toSuccession.length)).carrier) : Manifold.IdealSheaf.ord (((self.functor.fam T hT).seqOn U hU).toSuccession.markedTransformSeq (T.pullback (M.inclusion U) ⋯).I m (Fin.last ((self.functor.fam T hT).seqOn U hU).toSuccession.length)) x < ↑m
Theorem 107 (1) ("
max-ord I_r < m"), pointwise per open: the marked transform at the last stage overUhas order< mat every point. - commutesWithLocalIsos : self.functor.CommutesWithLocalIsos
Theorem 107 (2): the functor commutes with local analytic isomorphisms.
- indifferentToEmptyMembers : self.functor.IndifferentToEmptyMembers
The functor is indifferent to empty boundary members.
Instances For
The per-open bridge from the finite layer #
A finite blow-up-sequence functor B on a class closed under
restriction to opens (hres) that commutes with open embeddings (hopen) gives a family
functor B.toFamily, its value on U the finite value on the restricted triple. compat is
the open-embedding clause of [Kol07, 34.1] along the open inclusion restrictLE; noEmptyCenters
is B.noEmptyCenters. The finite functor thereby yields a family functor with no further proof.
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- One or more equations did not get rendered due to their size.
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A member's preimage under the open inclusion is nonempty only if the member is, so the global
finiteness of the nonempty members restricts to any open (no relative compactness needed — the
weaker hypothesis beside boClass_pullback_inclusion).
The intrinsic class BOClass m restricts to any open — the order bound
restricts (IdealSheaf.ord_pullback_of_isLocalDiffeomorphAt) and the finiteness from
finite_nonempty_pullback_inclusion (weaker hypotheses than boClass_pullback_inclusion: no
relative compactness).
The intrinsic class BMOClass m (no order bound) restricts to any open.
Universes: the family records live in Type (u+1), #
exactly the universe of the finite record BMOanData (both quantify over
AnalyticManifold.{u}).