File size: 20,726 Bytes
8e4d533
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
import OAI.Geometry.ComplexBundle.Kernel
import OAI.Geometry.ComplexBundle.Orthonormal

namespace OAI

noncomputable section

/-! Local and global topology and splitting of frame complement bundles. -/

section
open Bundle Topology
namespace Kaplansky
open ComplexGrassmann
namespace ContinuousOrthonormalStageFrame

section
variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)

/-- The complement is the kernel of the actual frame coefficient map. -/
theorem analysis_ker (y : ProjectiveProduct K) :
    LinearMap.ker (frameAnalysis (f.vector y)) =
      (Submodule.span ℂ (Set.range (f.vector y)))ᗮ := by
  ext v
  rw [LinearMap.mem_ker,Submodule.mem_orthogonal]
  constructor
  · intro h u hu
    have hz (i : Fin d) : inner ℂ (f.vector y i) v=0 :=
      congrArg (fun w : EuclideanSpace ℂ (Fin d) => w i) h
    induction hu using Submodule.span_induction with
    | mem u hu =>
      obtain ⟨i, rfl⟩ := hu
      exact hz i
    | zero => exact inner_zero_left _
    | add u w hu hw ihu ihw =>
      exact (inner_add_left u w _).trans (by rw [ihu, ihw, zero_add])
    | smul c u hu ihu =>
      exact (inner_smul_left u _ c).trans (by rw [ihu, mul_zero])
  · intro h
    apply (EuclideanSpace.equiv (Fin d) ℂ).injective
    funext i
    exact h _ (Submodule.subset_span ⟨i,rfl⟩)

theorem analysis_surjective (y : ProjectiveProduct K) :
    Function.Surjective (frameAnalysis (f.vector y)) :=
  fun v => ⟨frameSynthesis (f.vector y) v,frameAnalysis_synthesis _ (f.orthonormal y) v⟩

/-- The actual kernel has constant rank, with no complement-bundle premise. -/
theorem analysis_kernel_finrank (y : ProjectiveProduct K) :
    Module.finrank ℂ (LinearMap.ker (frameAnalysis (f.vector y))) = Fintype.card a.Slot-d := by
  rw [f.analysis_ker]
  have h := f.complement_finrank y
  omega

end

section
variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)
variable (e : Trivialization a.Model (π a.Model a.Fiber)) [e.IsLinear ℂ]

/-- The coefficient map in an ambient chart. -/
def localAnalysis (y : e.baseSet) : a.Model →L[ℂ] EuclideanSpace ℂ (Fin d) :=
  ((frameAnalysis (f.vector y.val)).comp (e.symmL ℂ y.val).toLinearMap).toContinuousLinearMap

theorem continuous_localAnalysis : Continuous (f.localAnalysis e) := by
  apply continuous_clm_apply.mpr
  intro v
  have hc : Continuous (fun y : e.baseSet =>
      TotalSpace.mk' a.Model y.val (e.symmL ℂ y.val v)) := by
    have h := e.continuousOn_symm.comp_continuous
      (continuous_subtype_val.prodMk continuous_const)
      (fun y : e.baseSet => show (y.val,v) ∈ e.baseSet ×ˢ Set.univ from ⟨y.property,Set.mem_univ _⟩)
    exact h.congr (fun y => by simp only [Function.comp_apply,e.symmL_apply y.property])
  exact f.continuous_analysis.comp hc

theorem localAnalysis_surjective (y : e.baseSet) : Function.Surjective (f.localAnalysis e y) := by
  intro v
  refine ⟨e.continuousLinearMapAt ℂ y.val (frameSynthesis (f.vector y.val) v),?_⟩
  change frameAnalysis (f.vector y.val)
    (e.symmL ℂ y.val (e.continuousLinearMapAt ℂ y.val (frameSynthesis (f.vector y.val) v)))=v
  rw [e.symmL_continuousLinearMapAt y.property,frameAnalysis_synthesis _ (f.orthonormal y.val)]

/-- A continuous surjective family on every ambient chart, constructed from
an arbitrary continuous orthonormal frame. -/
def localKernelFamily : SmoothKernel.SurjectiveFamily e.baseSet a.Model (EuclideanSpace ℂ (Fin d)) where
  map := f.localAnalysis e
  continuous := f.continuous_localAnalysis e
  surjective := f.localAnalysis_surjective e

end

section
variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)

/-- The actual complement, with the ambient bundle's subspace topology. -/
abbrev ComplementTotal := {z : TotalSpace a.Model a.Fiber //
  z.2 ∈ (Submodule.span ℂ (Set.range (f.vector z.proj)))ᗮ}

variable (e : Trivialization a.Model (π a.Model a.Fiber)) [e.IsLinear ℂ]
abbrev LocalComplementTotal := {z : f.ComplementTotal // z.val.proj ∈ e.baseSet}

def complementToLocalKernel (z : f.LocalComplementTotal e) :
    (f.localKernelFamily e).IncidenceTotal := by
  refine ⟨(⟨z.val.val.proj,z.property⟩,e.continuousLinearMapAt ℂ z.val.val.proj z.val.val.2),?_⟩
  change frameAnalysis (f.vector z.val.val.proj)
    (e.symmL ℂ z.val.val.proj (e.continuousLinearMapAt ℂ z.val.val.proj z.val.val.2))=0
  rw [e.symmL_continuousLinearMapAt z.property]
  exact (show z.val.val.2 ∈ LinearMap.ker (frameAnalysis (f.vector z.val.val.proj)) from
    (f.analysis_ker z.val.val.proj).symm ▸ z.val.property)

def localKernelToComplement (z : (f.localKernelFamily e).IncidenceTotal) :
    f.LocalComplementTotal e := by
  refine ⟨⟨⟨z.val.1.val,e.symmL ℂ z.val.1.val z.val.2⟩,?_⟩,z.val.1.property⟩
  rw [← f.analysis_ker]
  exact z.property

theorem continuous_complementToLocalKernel : Continuous (f.complementToLocalKernel e) := by
  have hp : Continuous (fun z : f.LocalComplementTotal e => z.val.val.proj) :=
    (FiberBundle.continuous_proj _ _).comp (continuous_subtype_val.comp continuous_subtype_val)
  have he : Continuous (fun z : f.LocalComplementTotal e =>
      e.continuousLinearMapAt ℂ z.val.val.proj z.val.val.2) := by
    have hc := (e.continuousOn.comp_continuous
      (continuous_subtype_val.comp continuous_subtype_val)
      (fun z : f.LocalComplementTotal e => e.mem_source.mpr z.property)).snd
    exact hc.congr (fun z => (e.continuousLinearMapAt_apply_of_mem ℂ z.property _).symm)
  exact ((hp.subtype_mk _).prodMk he).subtype_mk _

theorem continuous_localKernelToComplement : Continuous (f.localKernelToComplement e) := by
  have hp : Continuous (fun z : (f.localKernelFamily e).IncidenceTotal => z.val.1.val) :=
    continuous_subtype_val.comp (continuous_fst.comp continuous_subtype_val)
  have hv : Continuous (fun z : (f.localKernelFamily e).IncidenceTotal => z.val.2) :=
    continuous_snd.comp continuous_subtype_val
  have hc := e.continuousOn_symm.comp_continuous (hp.prodMk hv)
    (fun z : (f.localKernelFamily e).IncidenceTotal =>
      show (z.val.1.val,z.val.2) ∈ e.baseSet ×ˢ Set.univ from ⟨z.val.1.property,Set.mem_univ _⟩)
  have hs : Continuous (fun z : (f.localKernelFamily e).IncidenceTotal =>
      TotalSpace.mk' a.Model z.val.1.val (e.symmL ℂ z.val.1.val z.val.2)) :=
    hc.congr (fun z => by simp only [Function.comp_apply,e.symmL_apply z.val.1.property])
  exact (hs.subtype_mk _).subtype_mk _

/-- A homeomorphism to the genuine kernel incidence set over an ambient
chart. Both spaces retain their ambient subspace topologies. -/
def localComplementKernelHomeomorph : f.LocalComplementTotal e ≃ₜ
    (f.localKernelFamily e).IncidenceTotal where
  toFun := f.complementToLocalKernel e
  invFun := f.localKernelToComplement e
  left_inv z := by
    apply Subtype.ext
    apply Subtype.ext
    obtain ⟨⟨⟨y,v⟩,hv⟩,hy⟩ := z
    exact congrArg (TotalSpace.mk' a.Model y) (e.symmL_continuousLinearMapAt hy v)
  right_inv z := by
    apply Subtype.ext
    apply Prod.ext
    · rfl
    · exact e.continuousLinearMapAt_symmL z.val.1.property z.val.2
  continuous_toFun := f.continuous_complementToLocalKernel e
  continuous_invFun := f.continuous_localKernelToComplement e

/-- The local ordinary kernel bundle realizes the exact orthogonal
complement, not an independently assigned topology on the same fibers. -/
def localComplementBundleHomeomorph :
    TotalSpace (SmoothKernel.KernelModel a.Model (EuclideanSpace ℂ (Fin d)))
      (f.localKernelFamily e).realCore.Fiber ≃ₜ f.LocalComplementTotal e :=
  (f.localKernelFamily e).incidenceHomeomorph.trans (f.localComplementKernelHomeomorph e).symm

end

section
variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)

abbrev ComplementModel (_ : ContinuousOrthonormalStageFrame a d) := SmoothKernel.KernelModel a.Model (EuclideanSpace ℂ (Fin d))
abbrev ComplementFiber (y : ProjectiveProduct K) :=
  ↥(Submodule.span ℂ (Set.range (f.vector y)))ᗮ

def complementTotalEquiv : TotalSpace f.ComplementModel f.ComplementFiber ≃ f.ComplementTotal where
  toFun z := ⟨⟨z.proj,z.2.val⟩,z.2.property⟩
  invFun z := ⟨z.val.proj,⟨z.val.2,z.property⟩⟩
  left_inv _ := rfl
  right_inv _ := rfl

instance complementTotalTopology : TopologicalSpace (TotalSpace f.ComplementModel f.ComplementFiber) :=
  TopologicalSpace.induced f.complementTotalEquiv inferInstance

def complementTotalHomeomorph : TotalSpace f.ComplementModel f.ComplementFiber ≃ₜ f.ComplementTotal :=
  f.complementTotalEquiv.toHomeomorphOfIsInducing ⟨rfl⟩

def complementInclusion (z : TotalSpace f.ComplementModel f.ComplementFiber) : TotalSpace a.Model a.Fiber :=
  ⟨z.proj,z.2.val⟩

theorem complementInclusion_isInducing : IsInducing f.complementInclusion :=
  IsInducing.subtypeVal.comp f.complementTotalHomeomorph.isInducing

theorem complement_totalSpaceMk_isInducing (y : ProjectiveProduct K) :
    IsInducing (TotalSpace.mk (F := f.ComplementModel) (E := f.ComplementFiber) y) := by
  have h : IsInducing (fun v : f.ComplementFiber y =>
      TotalSpace.mk' a.Model y v.val) :=
    (FiberBundle.totalSpaceMk_isInducing a.Model a.Fiber y).comp IsInducing.subtypeVal
  exact (f.complementInclusion_isInducing.of_comp_iff).mp h

end

section
variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)
variable (e : Trivialization a.Model (π a.Model a.Fiber)) [e.IsLinear ℂ]

def complementLocalTriv (i : e.baseSet) : Trivialization f.ComplementModel
    (fun z : f.LocalComplementTotal e => (⟨z.val.val.proj,z.property⟩ : e.baseSet)) :=
  ((f.localKernelFamily e).realCore.localTriv i).compHomeomorph
    (f.localComplementBundleHomeomorph e).symm

theorem complementLocalTriv_apply (i : e.baseSet) (z : f.LocalComplementTotal e) :
    (f.complementLocalTriv e i z).2 =
      (f.localKernelFamily e).toModel i (e.continuousLinearMapAt ℂ z.val.val.proj z.val.val.2) := by
  exact (f.localKernelFamily e).fromIncidence_chart (f.complementToLocalKernel e z) i

/-- Extend the locally constructed kernel chart over its open base into
the actual global complement total space. -/
def complementAmbientTriv (i : e.baseSet) : Trivialization f.ComplementModel
    (fun z : f.ComplementTotal => z.val.proj) :=
  Trivialization.domExtend
    (e.open_baseSet.preimage ((FiberBundle.continuous_proj _ _).comp continuous_subtype_val))
    ((f.complementLocalTriv e i).codExtend e.open_baseSet ⟨i.val,i.property⟩)

def complementTriv (i : e.baseSet) : Trivialization f.ComplementModel
    (π f.ComplementModel f.ComplementFiber) :=
  (f.complementAmbientTriv e i).compHomeomorph f.complementTotalHomeomorph

theorem complementTriv_baseSet (i : e.baseSet) :
    (f.complementTriv e i).baseSet = Subtype.val '' (f.localKernelFamily e).baseSet i := rfl

theorem complementTriv_apply (i : e.baseSet) (y : ProjectiveProduct K) (hy : y ∈ e.baseSet)
    (v : f.ComplementFiber y) :
    (f.complementTriv e i ⟨y,v⟩).2 =
      (f.localKernelFamily e).toModel i (e.continuousLinearMapAt ℂ y v.val) := by
  classical
  change (((f.complementLocalTriv e i).codExtend e.open_baseSet ⟨i.val,i.property⟩).toPretrivialization.domExtend
    (f.complementTotalEquiv ⟨y,v⟩)).2 = _
  dsimp only [Pretrivialization.domExtend]
  change (if h : y ∈ e.baseSet then
    ((f.complementLocalTriv e i).codExtend e.open_baseSet ⟨i.val,i.property⟩)
      ⟨f.complementTotalEquiv ⟨y,v⟩,h⟩ else _).2 = _
  rw [dite_eq_left hy]
  exact f.complementLocalTriv_apply e i ⟨f.complementTotalEquiv ⟨y,v⟩,hy⟩

instance complementTriv_isLinear (i : e.baseSet) : (f.complementTriv e i).IsLinear ℂ where
  linear y hy := by
    rw [f.complementTriv_baseSet] at hy
    obtain ⟨z,hz,rfl⟩ := hy
    let L : f.ComplementFiber z.val →ₗ[ℂ] f.ComplementModel :=
      ((f.localKernelFamily e).toModel i).toLinearMap.comp
        ((e.continuousLinearMapAt ℂ z.val).toLinearMap.comp (Submodule.subtype _))
    have he : (fun v : f.ComplementFiber z.val => (f.complementTriv e i ⟨z.val,v⟩).2)=L := by
      funext v
      exact f.complementTriv_apply e i z.val z.property v
    rw [he]
    exact L.isLinear

end

variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)

def complementTrivializationAt (y : ProjectiveProduct K) :
    Trivialization f.ComplementModel (π f.ComplementModel f.ComplementFiber) :=
  f.complementTriv (trivializationAt a.Model a.Fiber y)
    ⟨y,mem_baseSet_trivializationAt a.Model a.Fiber y⟩

theorem mem_complementTrivializationAt (y : ProjectiveProduct K) :
    y ∈ (f.complementTrivializationAt y).baseSet := by
  rw [complementTrivializationAt,f.complementTriv_baseSet]
  exact ⟨_,(f.localKernelFamily (trivializationAt a.Model a.Fiber y)).center_mem _,rfl⟩

instance complementFiberBundle : FiberBundle f.ComplementModel f.ComplementFiber where
  totalSpaceMk_isInducing' := f.complement_totalSpaceMk_isInducing
  trivializationAtlas' := Set.range f.complementTrivializationAt
  trivializationAt' := f.complementTrivializationAt
  mem_baseSet_trivializationAt' := f.mem_complementTrivializationAt
  trivialization_mem_atlas' y := ⟨y,rfl⟩

instance complementTrivializationAt_isLinear (y : ProjectiveProduct K) :
    (f.complementTrivializationAt y).IsLinear ℂ := by
  unfold complementTrivializationAt
  infer_instance

theorem continuousOn_complement_coordChange
    (e e' : Trivialization f.ComplementModel (π f.ComplementModel f.ComplementFiber))
    [e.IsLinear ℂ] [e'.IsLinear ℂ] :
    ContinuousOn (fun y => (e.coordChangeL ℂ e' y : f.ComplementModel →L[ℂ] f.ComplementModel))
      (e.baseSet ∩ e'.baseSet) := by
  apply continuousOn_clm_apply.mpr
  intro v
  have hi : ContinuousOn (fun y : ProjectiveProduct K =>
      TotalSpace.mk' f.ComplementModel y (e.symm y v)) (e.baseSet ∩ e'.baseSet) :=
    e.continuousOn_symm.comp (continuousOn_id.prodMk continuousOn_const)
      (fun y hy => ⟨hy.1,Set.mem_univ _⟩)
  have hc := (e'.continuousOn.comp hi (fun y hy => e'.mem_source.mpr hy.2)).snd
  exact hc.congr (fun y hy => e.coordChangeL_apply e' hy v)

/-- The full orthogonal complement is an ordinary complex vector bundle,
with charts constructed from the frame and the inherited ambient topology. -/
instance complementVectorBundle : VectorBundle ℂ f.ComplementModel f.ComplementFiber where
  trivialization_linear' := by
    rintro _ ⟨y,rfl⟩
    exact f.complementTrivializationAt_isLinear y
  continuousOn_coordChange' := by
    rintro _ _ ⟨y,rfl⟩ ⟨z,rfl⟩
    exact f.continuousOn_complement_coordChange _ _

theorem complementBundle_rank (y : ProjectiveProduct K) :
    Module.finrank ℂ (f.ComplementFiber y) = Fintype.card a.Slot-d := by
  change Module.finrank ℂ (Submodule.span ℂ (Set.range (f.vector y)))ᗮ = _
  have h := f.complement_finrank y
  omega

end ContinuousOrthonormalStageFrame
end Kaplansky

end

open Bundle Topology
namespace Kaplansky
open ComplexGrassmann
namespace ContinuousOrthonormalStageFrame
variable {ι : Type*} {K : ι → ℕ} {a : LineStage K} {d : ℕ}
variable (f : ContinuousOrthonormalStageFrame a d)

theorem analysis_complement (y : ProjectiveProduct K) (v : f.ComplementFiber y) :
    frameAnalysis (f.vector y) v.val=0 := by
  change v.val ∈ LinearMap.ker (frameAnalysis (f.vector y))
  rw [f.analysis_ker]
  exact v.property

theorem projection_synthesis (y : ProjectiveProduct K) (v : EuclideanSpace ℂ (Fin d)) :
    f.projection y (frameSynthesis (f.vector y) v)=frameSynthesis (f.vector y) v := by
  change frameSynthesis (f.vector y) (frameAnalysis (f.vector y) (frameSynthesis (f.vector y) v))=_
  rw [frameAnalysis_synthesis _ (f.orthonormal y)]

/-- The actual fiber decomposition into the full orthogonal complement and
the trivial frame summand. No alignment with the original line summands. -/
def complementSplitLinearEquiv (y : ProjectiveProduct K) :
    (f.ComplementFiber y × EuclideanSpace ℂ (Fin d)) ≃ₗ[ℂ] a.Fiber y where
  toFun v := v.1.val+frameSynthesis (f.vector y) v.2
  invFun v := (⟨f.complementProjection y v,f.complementProjection_mem y v⟩,frameAnalysis (f.vector y) v)
  left_inv v := by
    apply Prod.ext
    · apply Subtype.ext
      change (v.1.val+frameSynthesis (f.vector y) v.2) -
        f.projection y (v.1.val+frameSynthesis (f.vector y) v.2)=v.1.val
      rw [map_add,f.projection_eq_zero_of_orthogonal y v.1.val v.1.property,f.projection_synthesis]
      simp
    · change frameAnalysis (f.vector y) (v.1.val+frameSynthesis (f.vector y) v.2)=v.2
      rw [map_add,f.analysis_complement,frameAnalysis_synthesis _ (f.orthonormal y),zero_add]
  right_inv v := by
    change v-f.projection y v+f.projection y v=v
    exact sub_add_cancel _ _
  map_add' v w := by
    change v.1.val+w.1.val+frameSynthesis (f.vector y) (v.2+w.2)=_
    rw [map_add]
    abel
  map_smul' c v := by
    change c • v.1.val+frameSynthesis (f.vector y) (c • v.2)=_
    exact (congrArg (fun w => c • v.1.val + w)
      ((frameSynthesis (f.vector y)).map_smul c v.2)).trans
        (smul_add c v.1.val (frameSynthesis (f.vector y) v.2)).symm

abbrev ComplementSplitTotal :=
  TotalSpace f.ComplementModel f.ComplementFiber × EuclideanSpace ℂ (Fin d)

def complementAssemble (z : f.ComplementSplitTotal) : TotalSpace a.Model a.Fiber :=
  ⟨z.1.proj,f.complementSplitLinearEquiv z.1.proj (z.1.2,z.2)⟩

def complementDisassemble (z : TotalSpace a.Model a.Fiber) : f.ComplementSplitTotal :=
  (⟨z.proj,(f.complementSplitLinearEquiv z.proj).symm z.2 |>.1⟩,
    (f.complementSplitLinearEquiv z.proj).symm z.2 |>.2)

theorem continuous_complementAssemble : Continuous f.complementAssemble := by
  have hv : Continuous (fun z : f.ComplementSplitTotal =>
      TotalSpace.mk' a.Model z.1.proj z.1.2.val) :=
    f.complementInclusion_isInducing.continuous.comp continuous_fst
  have hp : Continuous (fun z : f.ComplementSplitTotal => z.1.proj) :=
    (FiberBundle.continuous_proj _ _).comp continuous_fst
  have hw : Continuous (fun z : f.ComplementSplitTotal =>
      TotalSpace.mk' a.Model z.1.proj (frameSynthesis (f.vector z.1.proj) z.2)) :=
    f.continuous_synthesis.comp (hp.prodMk continuous_snd)
  apply continuous_iff_continuousAt.mpr
  intro z
  rw [FiberBundle.continuousAt_totalSpace]
  refine ⟨hp.continuousAt,?_⟩
  have hvc := (FiberBundle.continuousAt_totalSpace a.Model _ (x₀ := z)).mp hv.continuousAt |>.2
  have hwc := (FiberBundle.continuousAt_totalSpace a.Model _ (x₀ := z)).mp hw.continuousAt |>.2
  apply (hvc.add hwc).congr_of_eventuallyEq
  let e := trivializationAt a.Model a.Fiber z.1.proj
  have hn := hp.continuousAt (e.open_baseSet.mem_nhds
    (mem_baseSet_trivializationAt a.Model a.Fiber z.1.proj))
  filter_upwards [hn] with w hw
  exact (e.linear ℂ hw).map_add w.1.2.val (frameSynthesis (f.vector w.1.proj) w.2)

theorem continuous_complementDisassemble : Continuous f.complementDisassemble := by
  have hc : Continuous (fun z : TotalSpace a.Model a.Fiber =>
      (⟨z.proj,⟨f.complementProjection z.proj z.2,f.complementProjection_mem z.proj z.2⟩⟩ :
        TotalSpace f.ComplementModel f.ComplementFiber)) :=
    f.complementInclusion_isInducing.continuous_iff.mpr f.continuous_complementProjection
  exact hc.prodMk f.continuous_analysis

/-- Global topological splitting of the actual bundle. The first factor
is the constructed complement vector bundle and the other factor is trivial. -/
def complementSplitHomeomorph : f.ComplementSplitTotal ≃ₜ TotalSpace a.Model a.Fiber where
  toFun := f.complementAssemble
  invFun := f.complementDisassemble
  left_inv z := by
    obtain ⟨⟨y,v⟩,w⟩ := z
    have h := (f.complementSplitLinearEquiv y).symm_apply_apply (v,w)
    change ((⟨y,((f.complementSplitLinearEquiv y).symm (f.complementSplitLinearEquiv y (v,w))).1⟩ : TotalSpace f.ComplementModel f.ComplementFiber),
      ((f.complementSplitLinearEquiv y).symm (f.complementSplitLinearEquiv y (v,w))).2)=((⟨y,v⟩ : TotalSpace f.ComplementModel f.ComplementFiber),w)
    rw [h]
  right_inv z := by
    obtain ⟨y,v⟩ := z
    exact congrArg (TotalSpace.mk' a.Model y) ((f.complementSplitLinearEquiv y).apply_symm_apply v)
  continuous_toFun := f.continuous_complementAssemble
  continuous_invFun := f.continuous_complementDisassemble

@[simp] theorem complementSplitHomeomorph_base (z : f.ComplementSplitTotal) :
    (f.complementSplitHomeomorph z).proj=z.1.proj := rfl

end ContinuousOrthonormalStageFrame
end Kaplansky

end

end OAI