openAI-math-dataset / lean /OAI /SetTheory /PartitionPrinciple /Models /GroundSuccessorInjections.lean
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import OAI.SetTheory.PartitionPrinciple.Geometry.GroundNaturalNumbers
namespace OAI
namespace PartitionPilot.Forcing
universe u
theorem setSuccessor_injective : Function.Injective (fun x : ZFSet.{u} => insert x x) := by
intro x y eq
change insert x x = insert y y at eq
have xy : x = y ∨ x ∈ y := ZFSet.mem_insert_iff.1 (eq ▸ ZFSet.mem_insert x x)
have yx : y = x ∨ y ∈ x := ZFSet.mem_insert_iff.1 (eq.symm ▸ ZFSet.mem_insert y y)
rcases xy with eq | xy
· exact eq
· rcases yx with eq | yx
· exact eq.symm
· exact False.elim (ZFSet.mem_asymm xy yx)
theorem setSuccessor_ne_empty (x : ZFSet.{u}) : insert x x ≠ (∅ : ZFSet.{u}) := by
intro eq
exact ZFSet.notMem_empty x (eq ▸ ZFSet.mem_insert x x)
noncomputable def shiftedInjectionGraph (D f : ZFSet.{u}) : ZFSet.{u} :=
ZFSet.sep (fun z => ∃ x ∈ D, ∃ n ∈ ZFSet.omega,
z = ZFSet.pair x (insert n n) ∧ ZFSet.pair x n ∈ f) (ZFSet.prod D ZFSet.omega)
theorem mem_shiftedInjectionGraph (D f z : ZFSet.{u}) :
z ∈ shiftedInjectionGraph D f ↔ ∃ x ∈ D, ∃ n ∈ ZFSet.omega,
z = ZFSet.pair x (insert n n) ∧ ZFSet.pair x n ∈ f := by
rw [shiftedInjectionGraph, ZFSet.mem_sep]
constructor
· exact And.right
· intro h
obtain ⟨x, hx, n, hn, eq, rel⟩ := h
exact ⟨eq.symm ▸ ZFSet.pair_mem_prod.2 ⟨hx, ZFSet.omega_succ hn⟩,
x, hx, n, hn, eq, rel⟩
theorem pair_mem_shiftedInjectionGraph (D f x y : ZFSet.{u}) :
ZFSet.pair x y ∈ shiftedInjectionGraph D f ↔
x ∈ D ∧ ∃ n ∈ ZFSet.omega, y = insert n n ∧ ZFSet.pair x n ∈ f := by
rw [mem_shiftedInjectionGraph]
constructor
· rintro ⟨a, ha, n, hn, eq, rel⟩
obtain ⟨rfl, rfl⟩ := ZFSet.pair_inj.1 eq
exact ⟨ha, n, hn, rfl, rel⟩
· rintro ⟨hx, n, hn, rfl, rel⟩
exact ⟨x, hx, n, hn, rfl, rel⟩
theorem shiftedInjectionGraph_no_zero (D f x : ZFSet.{u}) :
ZFSet.pair x ∅ ∉ shiftedInjectionGraph D f := by
intro rel
obtain ⟨_, n, _, eq, _⟩ := (pair_mem_shiftedInjectionGraph D f x ∅).1 rel
exact setSuccessor_ne_empty n eq.symm
namespace InjectionCode
theorem shift {D f : ZFSet.{u}} (h : InjectionCode D ZFSet.omega f) :
InjectionCode D ZFSet.omega (shiftedInjectionGraph D f) := by
refine ⟨⟨fun _ hz => (ZFSet.mem_sep.1 hz).1, ?_⟩, ?_⟩
· intro x hx
obtain ⟨n, rel, unique⟩ := h.function.2 x hx
have hn := (ZFSet.pair_mem_prod.1 (h.function.1 rel)).2
refine ⟨insert n n, (pair_mem_shiftedInjectionGraph D f x _).2 ⟨hx, n, hn, rfl, rel⟩, ?_⟩
intro y hy
obtain ⟨_, m, _, eq, hm⟩ := (pair_mem_shiftedInjectionGraph D f x y).1 hy
rw [eq, unique m hm]
· intro x y z hx hy
obtain ⟨_, n, _, zn, xn⟩ := (pair_mem_shiftedInjectionGraph D f x z).1 hx
obtain ⟨_, m, _, zm, ym⟩ := (pair_mem_shiftedInjectionGraph D f y z).1 hy
have eq := setSuccessor_injective (zn.symm.trans zm)
exact h.injective x y m (eq ▸ xn) ym
end InjectionCode
noncomputable def adjoinInjectionGraph (D f a : ZFSet.{u}) : ZFSet.{u} :=
insert (ZFSet.pair a ∅) (shiftedInjectionGraph D f)
theorem pair_mem_adjoinInjectionGraph (D f a x y : ZFSet.{u}) :
ZFSet.pair x y ∈ adjoinInjectionGraph D f a ↔
(x = a ∧ y = ∅) ∨ ZFSet.pair x y ∈ shiftedInjectionGraph D f := by
rw [adjoinInjectionGraph, ZFSet.mem_insert_iff, ZFSet.pair_inj]
namespace InjectionCode
theorem adjoin_fresh {D f a : ZFSet.{u}} (h : InjectionCode D ZFSet.omega f) (fresh : a ∉ D) :
InjectionCode (insert a D) ZFSet.omega (adjoinInjectionGraph D f a) := by
have shifted := h.shift
refine ⟨⟨?_, ?_⟩, ?_⟩
· intro z hz
rcases ZFSet.mem_insert_iff.1 hz with rfl | hz
· exact ZFSet.pair_mem_prod.2 ⟨ZFSet.mem_insert a D, ZFSet.omega_zero⟩
· obtain ⟨x, hx, y, hy, rfl⟩ := ZFSet.mem_prod.1 (shifted.function.1 hz)
exact ZFSet.pair_mem_prod.2 ⟨ZFSet.mem_insert_of_mem a hx, hy⟩
· intro x hx
rcases ZFSet.mem_insert_iff.1 hx with eq | hx
· subst x
refine ⟨∅, (pair_mem_adjoinInjectionGraph D f a a ∅).2 (Or.inl ⟨rfl, rfl⟩), ?_⟩
intro y hy
rcases (pair_mem_adjoinInjectionGraph D f a a y).1 hy with eq | rel
· exact eq.2
· exact False.elim (fresh ((pair_mem_shiftedInjectionGraph D f a y).1 rel).1)
· obtain ⟨y, rel, unique⟩ := shifted.function.2 x hx
refine ⟨y, (pair_mem_adjoinInjectionGraph D f a x y).2 (Or.inr rel), ?_⟩
intro z hz
rcases (pair_mem_adjoinInjectionGraph D f a x z).1 hz with eq | rel
· exact False.elim (fresh (eq.1 ▸ hx))
· exact unique z rel
· intro x y z hx hy
rcases (pair_mem_adjoinInjectionGraph D f a x z).1 hx with eqx | shiftx
· rcases (pair_mem_adjoinInjectionGraph D f a y z).1 hy with eqy | shifty
· exact eqx.1.trans eqy.1.symm
· rw [eqx.2] at shifty
exact False.elim (shiftedInjectionGraph_no_zero D f y shifty)
· rcases (pair_mem_adjoinInjectionGraph D f a y z).1 hy with eqy | shifty
· rw [eqy.2] at shiftx
exact False.elim (shiftedInjectionGraph_no_zero D f x shiftx)
· exact shifted.injective x y z shiftx shifty
end InjectionCode
end PartitionPilot.Forcing
namespace PartitionPilot.Forcing.BoundedFormula
open SetFormula
universe u
def shiftedInjectionEntryFormula {n} (z d o f : Fin n) : BoundedFormula n :=
exMem d (exMem o.succ (exMem o.succ.succ
(.conj (successorFormula 0 1)
(.conj (orderedPairFormula z.succ.succ.succ 2 0)
(pairMembershipFormula 2 1 f.succ.succ.succ)))))
theorem truth_shiftedInjectionEntryFormula {n} (z d o f : Fin n)
(env : Fin n → ZFSet.{u}) (omega : env o = ZFSet.omega) :
Truth (shiftedInjectionEntryFormula z d o f) env ↔
∃ x ∈ env d, ∃ m ∈ ZFSet.omega,
env z = ZFSet.pair x (insert m m) ∧ ZFSet.pair x m ∈ env f := by
simp only [shiftedInjectionEntryFormula, truth_exMem, Truth,
truth_successorFormula, truth_orderedPairFormula, truth_pairMembershipFormula]
change (∃ x ∈ env d, ∃ m ∈ env o, ∃ k ∈ env o,
k = insert m m ∧ env z = ZFSet.pair x k ∧ ZFSet.pair x m ∈ env f) ↔ _
rw [omega]
constructor
· rintro ⟨x, hx, m, hm, k, _, rfl, eq, rel⟩
exact ⟨x, hx, m, hm, eq, rel⟩
· rintro ⟨x, hx, m, hm, eq, rel⟩
exact ⟨x, hx, m, hm, insert m m, ZFSet.omega_succ hm, rfl, eq, rel⟩
end PartitionPilot.Forcing.BoundedFormula
namespace PartitionPilot.Forcing.TransitiveGround
open SetFormula
universe u
variable (M : TransitiveGround.{u})
theorem insert_mem (pairing : Realize M.sets SetFormula.pairing Fin.elim0)
(unions : Realize M.sets SetFormula.union Fin.elim0)
{a D : ZFSet.{u}} (ha : a ∈ M.sets) (hD : D ∈ M.sets) : insert a D ∈ M.sets := by
have single : ({a} : ZFSet.{u}) ∈ M.sets := by
simpa only [ZFSet.pair_eq_singleton] using M.unorderedPair_mem pairing ha ha
have joined := M.binary_union_mem pairing unions single hD
have eq : ({a} : ZFSet.{u}) ∪ D = insert a D := by
apply ZFSet.ext
intro z
rw [ZFSet.mem_union, ZFSet.mem_singleton, ZFSet.mem_insert_iff]
exact eq ▸ joined
theorem shiftedInjectionGraph_mem
(pairing : Realize M.sets SetFormula.pairing Fin.elim0)
(unions : Realize M.sets SetFormula.union Fin.elim0)
(powers : Realize M.sets powerSet Fin.elim0) (separation : SeparationSchema M.sets)
(infinite : Realize M.sets infinity Fin.elim0)
{D f : ZFSet.{u}} (hD : D ∈ M.sets) (hf : f ∈ M.sets) :
shiftedInjectionGraph D f ∈ M.sets := by
have hO := M.omega_mem separation infinite
have bound := M.prod_mem pairing unions powers separation hD hO
let params := extend D (extend ZFSet.omega (extend f Fin.elim0))
have members : ∀ i, params i ∈ M.sets :=
Fin.cases hD (Fin.cases hO (Fin.cases hf (fun i => Fin.elim0 i)))
have selected := M.separation_mem separation
(BoundedFormula.shiftedInjectionEntryFormula 0 1 2 3).toFormula params members bound
have eq : ZFSet.sep (fun z => Realize M.sets
(BoundedFormula.shiftedInjectionEntryFormula 0 1 2 3).toFormula (extend z params))
(ZFSet.prod D ZFSet.omega) = shiftedInjectionGraph D f := by
apply ZFSet.ext
intro z
rw [ZFSet.mem_sep, shiftedInjectionGraph, ZFSet.mem_sep]
apply and_congr_right
intro hz
exact (BoundedFormula.realize_toFormula M _ _
(Fin.cases (M.transitive bound hz) members)).trans
(BoundedFormula.truth_shiftedInjectionEntryFormula 0 1 2 3 (extend z params) rfl)
exact eq ▸ selected
theorem adjoinInjectionGraph_mem
(pairing : Realize M.sets SetFormula.pairing Fin.elim0)
(unions : Realize M.sets SetFormula.union Fin.elim0)
(powers : Realize M.sets powerSet Fin.elim0) (separation : SeparationSchema M.sets)
(infinite : Realize M.sets infinity Fin.elim0)
{D f a : ZFSet.{u}} (hD : D ∈ M.sets) (hf : f ∈ M.sets) (ha : a ∈ M.sets) :
adjoinInjectionGraph D f a ∈ M.sets :=
M.insert_mem pairing unions
(M.orderedPair_mem pairing ha (M.empty_mem ⟨a, ha⟩))
(M.shiftedInjectionGraph_mem pairing unions powers separation infinite hD hf)
theorem groundEmbeddable_insert
(pairing : Realize M.sets SetFormula.pairing Fin.elim0)
(unions : Realize M.sets SetFormula.union Fin.elim0)
(powers : Realize M.sets powerSet Fin.elim0) (separation : SeparationSchema M.sets)
(infinite : Realize M.sets infinity Fin.elim0)
{D a : ZFSet.{u}} (hD : D ∈ M.sets) (ha : a ∈ M.sets)
(small : M.groundEmbeddable D ZFSet.omega) :
M.groundEmbeddable (insert a D) ZFSet.omega := by
classical
by_cases member : a ∈ D
· have eq : insert a D = D := by
apply ZFSet.ext
intro z
rw [ZFSet.mem_insert_iff]
exact ⟨fun h => h.elim (fun eq => eq.symm ▸ member) id, Or.inr⟩
exact eq.symm ▸ small
· obtain ⟨f, hf, code⟩ := small
exact ⟨adjoinInjectionGraph D f a,
M.adjoinInjectionGraph_mem pairing unions powers separation infinite hD hf ha,
code.adjoin_fresh member⟩
end PartitionPilot.Forcing.TransitiveGround
end OAI