The monomial phase commutes with local isomorphisms up to empty blow-ups #
The second condition of [Kol07, 34.1] and the compatibility of [Wlo09, Theorem 2.0.3 (4)] (in the
sense of [Wlo09, Definition 3.2.6]) for the monomial phase at the mark 1: along a local analytic
isomorphism g : N → M the complete phase of the pulled-back triple is the pull-back of the
complete phase of T with its empty blow-ups deleted,
step2bPhase k' (T.pullback g) = ((step2bPhase k T).pullback g).eraseEmpty for every
k ≥ step2bMeasure T and k' ≥ step2bMeasure (T.pullback g) (step2bPhase_pullback_eraseEmpty).
This gives the compatibility of the family of the phase and the half of its commutation with local
isomorphisms for open embeddings.
Induction on the fuel of T. At a step with centre Z (the positive locus of the top member j)
either g⁻¹(Z) is nonempty, and then j is the top member of the pull-back too, the centre pulls
back to the centre and the step to the step (Step2bPullback.lean), and the induction continues
along the lift of g; or g⁻¹(Z) is empty: the pulled-back blow-up is the empty one, which the
deletion of empty blow-ups removes by carrying the tail back along the isomorphism Bl_∅ N ≃ N
(eraseEmpty_cons_of_eq_empty, map_eq_pullback_symm); the triple of the tail carried back is the
pull-back with one empty member appended (emptyStepTriple_I,
isEmptyExtension_emptyStepTriple: the marked transform along an empty blow-up is the total
transform, birationalTransform_I_of_eq_empty), so the phase is indifferent to it
(Step2bEmpty.lean) and the carried-back phase is the pull-back's own (Step2bPullback.lean, the
isomorphism being surjective). The fuels are reconciled by the stabilisation of
Step2bMeasure.lean: the measure does not increase under pull-back (step2bMeasure_pullback_le)
nor under the deletion of empty members (step2bMeasure_le_of_isEmptyExtension).
The measure under pull-back and under empty extensions #
The supremum along a pulled-back member is at most the supremum along the member (the order
along the member transports along g, ordAlongIdeal_comap_of_isLocalDiffeomorphAt).
A nonempty member of the pull-back lies over a nonempty member.
The measure does not increase under pull-back along a local isomorphism.
Members with the same underlying set (and the same ideal sheaf) have the same sup.
The measure does not increase under an empty extension of the boundary.
Fuels above the measure give the same phase #
The measure is congruent under heterogeneous equality of triples over equal manifolds.
The empty case: the tail carried back along Bl_∅ N ≃ N #
The preimage of the centre, as a closed submanifold of N.
Equations
- ⋯ = ⋯
Instances For
The isomorphism Bl_∅ N ≃ N of the empty blow-up (emptyBlowUpDiffeomorph).
Equations
- Hironaka.Manifold.BMOmod.emptyIso T hfin hne g hg hZe = AnalyticManifold.BlowUpSequence.emptyBlowUpDiffeomorph ⋯ hZe
Instances For
Its inverse as an analytic map N → Bl_∅ N.
Equations
- Hironaka.Manifold.BMOmod.emptyBack T hfin hne g hg hZe = (Hironaka.Manifold.BMOmod.emptyIso T hfin hne g hg hZe).symm.toAnalyticMap
Instances For
The step pulled back along the lift and carried back to N.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Along the empty blow-up the marked transform is the total transform
(birationalTransform_I_of_eq_empty), so the carried-back ideal sheaf is the pull-back's own.
The carried-back boundary is the pull-back's boundary with one empty member appended.
The commutation theorem #
The second condition of [Kol07, 34.1] and the compatibility of [Wlo09, Theorem 2.0.3 (4)]:
along a local analytic isomorphism g, the complete phase of the pull-back is the pull-back of
the complete phase with its empty blow-ups deleted.