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Sync from openai/math@faee2cf485a8 (part 9)
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import OAI.Combinatorics.HadwigerCounterexample.PrimalSpaceCompression
namespace OAI
/-! # Bilinear Compression -/
noncomputable section
namespace HadwigerCounterexample
open Matrix LinearMap Submodule Module Finset
open scoped BigOperators
variable {p : Shape} {n : ℕ} {I J : Type} [Fintype I] [Fintype J]
def dqBound (p : Shape) (T H R : ℕ) := 2*(drow p T R+H)
private theorem pullM_fix (A : Mat I I) (P : Mat I I)
(h : ∀ x ∈ colSp P,Aᵀ *ᵥ x=x) (h' : ∀ x∈colSp Pᵀ,Aᵀ *ᵥ x=x) :
pullM A A P=P := by
rw [pullM_def,mat_mul_fix h]
have he := congrArg Matrix.transpose (mat_mul_fix h')
simpa only [Matrix.transpose_mul,Matrix.transpose_transpose] using he
private def dualSpace (M : Profile p n) (z : Place p) :=
colSp (if z.2 then M z.1 else (M z.1)ᵀ)
private theorem dualSpace_dim (M : Profile p n) (z : Place p) :
dim (dualSpace M z)=(M z.1).rank := by
cases z with
| mk i b =>
cases b; exact Matrix.rank_transpose _; rfl
private def jointShrink (A : Bool → Nendo p n) (B : Place p → Bool → Mat (Chan p) (Chan p))
(z : Place p) :=
∑ i : Bool,(liftM (IP p n i) (IP p n i) (rowShrink p (A i))+
liftM (IH p n i) (IH p n i) (B z i))
private theorem joint_ip (A : Bool → Nendo p n) (B : Place p → Bool → Mat (Chan p) (Chan p))
(z : Place p) (i : Bool) :
jointShrink A B z * IP p n i = IP p n i * rowShrink p (A i) := by
classical
simp only [jointShrink,Fintype.sum_bool,liftM_def,Matrix.add_mul,Matrix.mul_assoc,
IH_IP,Matrix.mul_zero,add_zero]
cases i <;> simp only [IP_self,IP_cross (show true≠false by decide),
IP_cross (show false≠true by decide),Matrix.mul_zero,Matrix.mul_one,add_zero,zero_add]
set_option maxHeartbeats 800000 in
theorem shrink_pure {f : Plan p n} {M : Individual p n} {P : PureForms p n}
(T H R : ℕ) (ht : ∀ z i,dim (sPin f z i)≤T) (hh : ∀ z i,dim (hPin f z i)≤H)
(hr : ∀ i e,(M i e).rank≤R)
(hp : P∈pureSpace p f) (he : obsPair p P=obsI p M) :
∃ Q∈pureSpace p f,obsPair p Q=obsPair p P ∧ ∀ e,(Q e).rank≤dqBound p T H R := by
classical
choose A hA hL hT using fun i => shrink_both (fun z => sPin f z i) (dualSpace (M i)) T R
(fun z => ht z i) (fun z => by rw [dualSpace_dim]; exact hr i z.1)
choose B hB using fun z i => proj_exists (hPin f z i) ⊥ disjoint_bot_right
let D := jointShrink A B
have hf (z : Place p) (x : Dir p n) (hx : x∈f z) : D z *ᵥ x=x := by
have h1 (i : Bool) : rowShrink p (A i) *ᵥ ((IP p n i)ᵀ *ᵥ x)=(IP p n i)ᵀ *ᵥ x :=
hA i z _ ⟨_,hx,rfl⟩
have h2 (i : Bool) : B z i *ᵥ ((IH p n i)ᵀ *ᵥ x)=(IH p n i)ᵀ *ᵥ x :=
(hB z i).fixes _ ⟨_,hx,rfl⟩
unfold D jointShrink
simp only [Matrix.sum_mulVec,Matrix.add_mulVec,liftM_def,← Matrix.mulVec_mulVec,h1,h2]
exact ip_decomp x
have hR (z : Place p) : (D z).rank ≤ dqBound p T H R := by
apply le_trans (mrk_sum_le ..)
have hx i :
(liftM (IP p n i) (IP p n i) (rowShrink p (A i))+
liftM (IH p n i) (IH p n i) (B z i)).rank ≤ drow p T R+H :=
(mrk_add_le ..).trans (add_le_add
((rank_lift_le ..).trans (hT i)) ((rank_lift_le ..).trans
((rank_maps (hPin f z i) (hB z i).onto).trans (hh z i))))
rw [Fintype.sum_bool,dqBound,two_mul]; exact add_le_add (hx _) (hx _)
let Q (e : Comp p.g) := pullM (D (e,true)) (D (e,false)) (P e)
have hG (i : Bool) (e : Comp p.g) : pullM (rowShrink p (A i)) (rowShrink p (A i)) (M i e)=
M i e := pullM_fix _ _ (hL i (e,true)) (hL i (e,false))
have hY (i : Bool) (e : Comp p.g) : eachF p Q i e=
pullM (rowShrink p (A i)) (rowShrink p (A i)) (eachF p P i e) := by
change pullM _ _ (Q e)=pullM _ _ (pullM _ _ _)
let G := IP p n i
have hw {I J K U V W : Type} [Fintype U] [Fintype V] [Fintype W] [Fintype I]
[Fintype J] [Fintype K] (L : Mat U I) (R : Mat V J)
(L' : Mat I K) (R' : Mat J W) (P : Mat U V) :
pullM L' R' (pullM L R P) = pullM (L*L') (R*R') P := by
unfold pullM
rw [liftM_comp,Matrix.transpose_mul,Matrix.transpose_mul]
unfold Q
rw [hw,hw]
have h (b) := joint_ip A B (e,b) i
rw [show D (e,true)*IP p n i=_ from h true, show D (e,false)*IP p n i=_ from h false]
refine ⟨Q,?_,?_,fun e => ?_⟩
· refine (pureSpace_mem _).mpr fun e => ?_
obtain ⟨h1,h2⟩ := box_kill.mp ((pureSpace_mem _).mp hp e)
unfold Q; rw [box_kill,pullM_def]; constructor
· intro x hx
simp only [transpose_mul,transpose_transpose,←Matrix.mulVec_mulVec,hf (e,true) x hx,h1 x hx,
mulVec_zero]
intro x hx
rw [← mulVec_mulVec,hf (e,false) x hx]
rw [← mulVec_mulVec,h2 x hx,mulVec_zero]
· rw [he,obsPair_each]
rw [obsPair_each] at he
change combineF p _=combineF p _
change combineF p _=combineF p _ at he
have he := (combineF_same ..).mp he
apply (combineF_same ..).mpr
intro i x hx
let y : Profile p n := fun e => liftM (rowShrink p (A i)) (rowShrink p (A i)) (x e)
rw [repF_rep,repF_rep]
have hv := he i y (shrink_X (A i) x hx)
rw [repF_rep,repF_rep] at hv
have hu (F : Individual p n) : (∑ e,mpair (F i e) (y e))=
∑ e,mpair (pullM (rowShrink p (A i)) (rowShrink p (A i)) (F i e)) (x e) :=
Finset.sum_congr rfl fun e _ => mpair_liftM ..
rw [hu,hu] at hv
simp_rw [← hY,hG] at hv
exact hv
unfold Q; rw [pullM_def]
exact ((Matrix.rank_mul_le_left ..).trans (Matrix.rank_mul_le_left ..)).trans
(by rw [Matrix.rank_transpose]; exact hR _)
end HadwigerCounterexample
end
end OAI