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Add lean source and binary files (part 59)
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import Lean.Elab.Tactic.Omega
import Mathlib.Algebra.BigOperators.Ring.Finset
import Mathlib.Algebra.Order.Archimedean.Real.Basic
import Mathlib.Algebra.Order.BigOperators.Group.Finset
import Mathlib.Algebra.Order.Floor.Ring
import Mathlib.Data.Finset.Card
import Mathlib.Data.Fintype.BigOperators
import Mathlib.Data.Fintype.Fin
import Mathlib.Basic.Real.Basic
import Mathlib.Logic.Equiv.Sum
import Mathlib.Tactic.FieldSimp
import Mathlib.Tactic.FinCases
import Mathlib.Tactic.Linarith
import Mathlib.Tactic.NormNum
import Mathlib.Tactic.Positivity
import Mathlib.Tactic.Ring
namespace OAI
noncomputable section
namespace BinPackingGap
def primaryScoreBound : ℕ := 100 ^ 11
def lossAllowance (c : ℕ) : ℕ := 25 * (c + 1) * (1 + 5 * primaryScoreBound)
def depthDemand (c : ℕ) (ρ : ℝ) : ℕ :=
Nat.ceil (max (72 * (lossAllowance c : ℝ)) (120 * (lossAllowance c : ℝ) / ρ))
def repetitions (P n K : ℕ) : ℕ := 100 * (P + n * K + 1)
theorem primaryScoreBound_pos : 0 < primaryScoreBound := by
unfold primaryScoreBound
positivity
theorem lossAllowance_pos (c : ℕ) : 0 < lossAllowance c := by
unfold lossAllowance
positivity
theorem primary_loss_lt_lossAllowance (c : ℕ) :
25 * c * (1 + 5 * primaryScoreBound) < lossAllowance c := by
unfold lossAllowance
apply mul_lt_mul_of_pos_right _ (by positivity)
exact mul_lt_mul_of_pos_left (Nat.lt_succ_self c) (by norm_num)
theorem depthDemand_ge_72_real (c : ℕ) (ρ : ℝ) :
72 * (lossAllowance c : ℝ) ≤ (depthDemand c ρ : ℝ) := by
exact (le_max_left _ _).trans (Nat.le_ceil _)
theorem depthDemand_ge_72 (c : ℕ) (ρ : ℝ) :
72 * lossAllowance c ≤ depthDemand c ρ := by
exact_mod_cast depthDemand_ge_72_real c ρ
theorem depthDemand_ge_120_div (c : ℕ) (ρ : ℝ) :
120 * (lossAllowance c : ℝ) / ρ ≤ (depthDemand c ρ : ℝ) := by
exact (le_max_right _ _).trans (Nat.le_ceil _)
theorem depthDemand_pos (c : ℕ) (ρ : ℝ) : 0 < depthDemand c ρ :=
lt_of_lt_of_le (Nat.mul_pos (by norm_num) (lossAllowance_pos c))
(depthDemand_ge_72 c ρ)
theorem depthDemand_one_le (c : ℕ) (ρ : ℝ) : 1 ≤ depthDemand c ρ :=
Nat.succ_le_of_lt (depthDemand_pos c ρ)
theorem depthDemand_ge_12 (c : ℕ) (ρ : ℝ) :
12 * lossAllowance c ≤ depthDemand c ρ := by
exact (Nat.mul_le_mul_right (lossAllowance c) (by norm_num : 12 ≤ 72)).trans
(depthDemand_ge_72 c ρ)
theorem depthDemand_spec (c : ℕ) (ρ : ℝ) :
1 ≤ depthDemand c ρ ∧
max (72 * (lossAllowance c : ℝ)) (120 * (lossAllowance c : ℝ) / ρ) ≤
(depthDemand c ρ : ℝ) :=
⟨depthDemand_one_le c ρ, Nat.le_ceil _⟩
theorem threshold_gap {d K : ℝ} (hd : 0 < d) (h72 : 72 * K ≤ d) :
d / 8 < d - 6 * K := by
linarith
theorem three_quarter_lower {d K x L : ℝ} (h72 : 72 * K ≤ d)
(hx : x ≤ d / 8) (hL : d - x - 9 * K ≤ L) : 3 * d / 4 ≤ L := by
linarith
theorem depthDemand_threshold_gap (c : ℕ) (ρ : ℝ) :
(depthDemand c ρ : ℝ) / 8 < (depthDemand c ρ : ℝ) - 6 * (lossAllowance c : ℝ) :=
threshold_gap (Nat.cast_pos.mpr (depthDemand_pos c ρ)) (depthDemand_ge_72_real c ρ)
theorem repetitions_pos (P n K : ℕ) : 0 < repetitions P n K := by
unfold repetitions
positivity
theorem repetitions_gt_P (P n K : ℕ) : P < repetitions P n K := by
have hnK : 0 ≤ n * K := Nat.zero_le _
unfold repetitions
nlinarith
theorem repetitions_cast (P n K : ℕ) :
(repetitions P n K : ℝ) = 100 * ((P : ℝ) + (n : ℝ) * K + 1) := by
simp [repetitions]
theorem edge_demand_exceeds_capacity_real {P n K d : ℝ}
(hP : 0 ≤ P) (hn : 0 ≤ n) (hK : 0 ≤ K) (hd : 1 ≤ d) :
d * (100 * (P + n * K + 1)) + 3 * n * K <
2 * (100 * (P + n * K + 1) - P) * (3 * d / 4) := by
have hd0 : 0 ≤ d := le_trans zero_le_one hd
have hdP : 0 ≤ d * P := mul_nonneg hd0 hP
have hnK : 0 ≤ n * K := mul_nonneg hn hK
have hrest : 0 ≤ (50 * d - 3) * (n * K) :=
mul_nonneg (by linarith) hnK
nlinarith
theorem edge_demand_exceeds_capacity (P n K d : ℕ) (hd : 1 ≤ d) :
(d : ℝ) * (repetitions P n K : ℝ) + 3 * (n : ℝ) * K <
2 * ((repetitions P n K : ℝ) - P) * (3 * (d : ℝ) / 4) := by
rw [repetitions_cast]
exact edge_demand_exceeds_capacity_real (Nat.cast_nonneg P) (Nat.cast_nonneg n)
(Nat.cast_nonneg K) (by exact_mod_cast hd)
theorem sixty_loss_div_le {ρ d K n : ℝ} (hρ : 0 < ρ) (hd : 0 < d)
(hK : 0 ≤ K) (hn : 0 ≤ n) (h120 : 120 * K / ρ ≤ d) :
60 * K * n / d ≤ ρ * n := by
have hmul := (div_le_iff₀ hρ).mp h120
have h60 : 60 * K ≤ ρ * d := by nlinarith
apply (div_le_iff₀ hd).mpr
calc
60 * K * n ≤ (ρ * d) * n := mul_le_mul_of_nonneg_right h60 hn
_ = (ρ * n) * d := by ring
theorem depthDemand_sixty_loss_div_le (c n : ℕ) {ρ : ℝ} (hρ : 0 < ρ) :
60 * (lossAllowance c : ℝ) * (n : ℝ) / (depthDemand c ρ : ℝ) ≤ ρ * n :=
sixty_loss_div_le hρ (Nat.cast_pos.mpr (depthDemand_pos c ρ))
(Nat.cast_nonneg _) (Nat.cast_nonneg _) (depthDemand_ge_120_div c ρ)
structure GraphInput where
n : ℕ
edges : List (Fin n × Fin n)
ordered : ∀ e ∈ edges, e.1 < e.2
distinct : edges.Nodup
namespace GraphInput
abbrev Vertex (G : GraphInput) := Fin G.n
abbrev Edge (G : GraphInput) := Fin G.edges.length
def left (G : GraphInput) (e : G.Edge) : G.Vertex := (G.edges[e]).1
def right (G : GraphInput) (e : G.Edge) : G.Vertex := (G.edges[e]).2
def IsCover (G : GraphInput) (C : Finset G.Vertex) : Prop :=
∀ e ∈ G.edges, e.1 ∈ C ∨ e.2 ∈ C
def CoverAtMost (G : GraphInput) (k : ℕ) : Prop :=
∃ C : Finset G.Vertex, G.IsCover C ∧ C.card ≤ k
end GraphInput
open scoped BigOperators
namespace GraphInput
def endpoint (G : GraphInput) (e : G.Edge) (s : Fin 2) : G.Vertex :=
if s = 0 then G.left e else G.right e
@[simp] theorem endpoint_zero (G : GraphInput) (e : G.Edge) :
G.endpoint e 0 = G.left e := by simp [endpoint]
@[simp] theorem endpoint_one (G : GraphInput) (e : G.Edge) :
G.endpoint e 1 = G.right e := by simp [endpoint]
theorem left_lt_right (G : GraphInput) (e : G.Edge) : G.left e < G.right e :=
G.ordered _ (List.getElem_mem e.isLt)
theorem left_ne_right (G : GraphInput) (e : G.Edge) : G.left e ≠ G.right e :=
(G.left_lt_right e).ne
theorem endpoint_injective (G : GraphInput) (e : G.Edge) :
Function.Injective (G.endpoint e) := by
intro s t h
have hs : s = 0 ∨ s = 1 := by omega
have ht : t = 0 ∨ t = 1 := by omega
rcases hs with rfl | rfl <;> rcases ht with rfl | rfl
· rfl
· exact False.elim (G.left_ne_right e (by simpa using h))
· exact False.elim (G.left_ne_right e (by simpa using h.symm))
· rfl
abbrev Incidence (G : GraphInput) (v : G.Vertex) :=
{es : G.Edge × Fin 2 // G.endpoint es.1 es.2 = v}
def incidenceEquiv (G : GraphInput) :
(Σ v : G.Vertex, G.Incidence v) ≃ G.Edge × Fin 2 :=
Equiv.sigmaFiberEquiv (fun es : G.Edge × Fin 2 => G.endpoint es.1 es.2)
def degree (G : GraphInput) (v : G.Vertex) : ℕ :=
Fintype.card (G.Incidence v)
theorem sum_degree (G : GraphInput) :
(∑ v : G.Vertex, G.degree v) = 2 * G.edges.length := by
have h := Fintype.card_congr (G.incidenceEquiv)
simpa [degree, Fintype.card_sigma, Fintype.card_prod, Nat.mul_comm] using h
abbrev IncidencePosition (G : GraphInput) (R : ℕ) (v : G.Vertex) :=
G.Incidence v × Fin R
abbrev JobCopy (G : GraphInput) (R d : ℕ) (v : G.Vertex) :=
G.IncidencePosition R v × Fin d
theorem card_incidencePosition (G : GraphInput) (R : ℕ) (v : G.Vertex) :
Fintype.card (G.IncidencePosition R v) = R * G.degree v := by
simp [IncidencePosition, degree, Nat.mul_comm]
theorem card_jobCopy (G : GraphInput) (R d : ℕ) (v : G.Vertex) :
Fintype.card (G.JobCopy R d v) = d * R * G.degree v := by
simp [JobCopy, IncidencePosition, degree, Nat.mul_comm, Nat.mul_left_comm,
Nat.mul_assoc]
theorem sum_card_jobCopy (G : GraphInput) (R d : ℕ) :
(∑ v : G.Vertex, Fintype.card (G.JobCopy R d v)) =
2 * d * G.edges.length * R := by
simp_rw [card_jobCopy]
rw [← Finset.mul_sum, sum_degree]
ac_rfl
end GraphInput
end BinPackingGap
section
open scoped BigOperators
namespace BinPackingGap
variable {V : Type*} [Fintype V] [DecidableEq V]
def thresholdCover (d : ℕ) (xplus : V → ℕ) : Finset V := by
classical
exact Finset.univ.filter fun v => (d : ℝ) / 8 < (xplus v : ℝ)
def largePlus (d K : ℕ) (xplus : V → ℕ) : Finset V := by
classical
exact Finset.univ.filter fun v => (d : ℝ) - 6 * K ≤ (xplus v : ℝ)
theorem residual_plus_le {d K : ℕ} (xplus xminus : V → ℕ)
(htotal : (∑ v, (xplus v + xminus v)) ≤ d * Fintype.card V)
(hside : ∀ v, d ≤ xplus v + 6 * K ∨ d ≤ xminus v + 6 * K) :
(∑ v, if v ∈ largePlus d K xplus then (0 : ℝ) else (xplus v : ℝ)) ≤
6 * (K : ℝ) * Fintype.card V := by
classical
let charge : V → ℝ := fun v =>
if v ∈ largePlus d K xplus then (xplus v : ℝ) else (xminus v : ℝ)
let rest : V → ℝ := fun v =>
if v ∈ largePlus d K xplus then 0 else (xplus v : ℝ)
have hcharge : ∀ v, (d : ℝ) - 6 * K ≤ charge v := by
intro v
by_cases hv : v ∈ largePlus d K xplus
· simpa only [charge, ite_eq_left hv] using (Finset.mem_filter.mp hv).2
· have hnot : ¬ ((d : ℝ) - 6 * K ≤ (xplus v : ℝ)) := by
simpa [largePlus] using hv
rcases hside v with hp | hm
· have hp' : (d : ℝ) ≤ (xplus v : ℝ) + 6 * K := by exact_mod_cast hp
exact (hnot (by linarith)).elim
· have hm' : (d : ℝ) ≤ (xminus v : ℝ) + 6 * K := by exact_mod_cast hm
simp only [charge, ite_eq_right hv]
linarith
have hcharged : (Fintype.card V : ℝ) * ((d : ℝ) - 6 * K) ≤ ∑ v, charge v := by
calc
_ = ∑ _v : V, ((d : ℝ) - 6 * K) := by
simp only [Finset.sum_const, Finset.card_univ, nsmul_eq_mul]
_ ≤ ∑ v, charge v := Finset.sum_le_sum fun v _ => hcharge v
have hpoint : ∀ v, charge v + rest v ≤ (xplus v : ℝ) + xminus v := by
intro v
dsimp only [charge, rest]
split_ifs <;> nlinarith [show (0 : ℝ) ≤ xplus v from Nat.cast_nonneg _,
show (0 : ℝ) ≤ xminus v from Nat.cast_nonneg _]
have hsum : (∑ v, charge v) + (∑ v, rest v) ≤
(d : ℝ) * Fintype.card V := by
calc
_ = ∑ v, (charge v + rest v) := (Finset.sum_add_distrib).symm
_ ≤ ∑ v, ((xplus v : ℝ) + xminus v) := Finset.sum_le_sum fun v _ => hpoint v
_ ≤ (d : ℝ) * Fintype.card V := by exact_mod_cast htotal
change (∑ v, rest v) ≤ _
nlinarith
theorem thresholdCover_card_le_fractions {d K k : ℕ} (xplus xminus : V → ℕ)
(hd : 0 < d) (h72 : 72 * K ≤ d)
(hplus : (∑ v, xplus v) ≤ d * k)
(htotal : (∑ v, (xplus v + xminus v)) ≤ d * Fintype.card V)
(hside : ∀ v, d ≤ xplus v + 6 * K ∨ d ≤ xminus v + 6 * K) :
((thresholdCover d xplus).card : ℝ) ≤
(d : ℝ) * k / ((d : ℝ) - 6 * K) + 48 * (K : ℝ) * Fintype.card V / d := by
classical
let A := largePlus d K xplus
let C := thresholdCover d xplus
let B := C \ A
have hd0 : (0 : ℝ) < d := by exact_mod_cast hd
have h72' : 72 * (K : ℝ) ≤ d := by exact_mod_cast h72
have hgap := threshold_gap hd0 h72'
have hden : 0 < (d : ℝ) - 6 * K := lt_trans (by positivity) hgap
have hAC : A ⊆ C := by
intro v hv
have hv' : (d : ℝ) - 6 * K ≤ (xplus v : ℝ) := (Finset.mem_filter.mp hv).2
exact Finset.mem_filter.mpr ⟨Finset.mem_univ v, hgap.trans_le hv'⟩
have hAlower : (A.card : ℝ) * ((d : ℝ) - 6 * K) ≤ ∑ v, (xplus v : ℝ) := by
calc
_ = ∑ _v ∈ A, ((d : ℝ) - 6 * K) := by
simp only [Finset.sum_const, nsmul_eq_mul]
_ ≤ ∑ v ∈ A, (xplus v : ℝ) :=
Finset.sum_le_sum fun v hv => (Finset.mem_filter.mp hv).2
_ ≤ ∑ v, (xplus v : ℝ) :=
Finset.sum_le_sum_of_subset_of_nonneg (Finset.subset_univ _) (by intros; positivity)
have hA : (A.card : ℝ) ≤ (d : ℝ) * k / ((d : ℝ) - 6 * K) := by
apply (le_div_iff₀ hden).mpr
exact hAlower.trans (by exact_mod_cast hplus)
let rest : V → ℝ := fun v => if v ∈ A then 0 else (xplus v : ℝ)
have hrest : (∑ v, rest v) ≤ 6 * (K : ℝ) * Fintype.card V :=
residual_plus_le xplus xminus htotal hside
have hBlower : (B.card : ℝ) * ((d : ℝ) / 8) ≤ ∑ v, rest v := by
calc
_ = ∑ _v ∈ B, ((d : ℝ) / 8) := by simp
_ ≤ ∑ v ∈ B, rest v := by
apply Finset.sum_le_sum
intro v hv
obtain ⟨hvC, hvA⟩ := Finset.mem_sdiff.mp hv
have hv' : (d : ℝ) / 8 < (xplus v : ℝ) := (Finset.mem_filter.mp hvC).2
simpa only [rest, ite_eq_right hvA] using hv'.le
_ ≤ ∑ v, rest v := by
apply Finset.sum_le_sum_of_subset_of_nonneg (Finset.subset_univ _)
intro v _ _
dsimp only [rest]
split_ifs <;> positivity
have hB : (B.card : ℝ) ≤ 48 * (K : ℝ) * Fintype.card V / d := by
apply (le_div_iff₀ hd0).mpr
nlinarith
have hcard : (C.card : ℝ) = (A.card : ℝ) + B.card := by
have hh := Finset.card_sdiff_add_card_eq_card hAC
dsimp only [B]
exact_mod_cast hh.symm.trans (Nat.add_comm _ _)
change (C.card : ℝ) ≤ _
rw [hcard]
exact add_le_add hA hB
theorem cover_fraction_bound {d K k n : ℝ} (hd : 0 < d) (hK : 0 ≤ K)
(hk0 : 0 ≤ k) (hkn : k ≤ n) (h12 : 12 * K ≤ d) :
d * k / (d - 6 * K) + 48 * K * n / d ≤ k + 60 * K * n / d := by
have hn : 0 ≤ n := hk0.trans hkn
have hden : 0 < d - 6 * K := by linarith
have hmult := mul_le_mul_of_nonneg_left hkn (show 0 ≤ 6 * K * d by positivity)
have hslack := mul_nonneg (show 0 ≤ 6 * K * n by positivity) (sub_nonneg.mpr h12)
have hfrac : 6 * K * k / (d - 6 * K) ≤ 12 * K * n / d := by
apply (div_le_div_iff₀ hden hd).mpr
nlinarith
have hid : d * k / (d - 6 * K) = k + 6 * K * k / (d - 6 * K) := by
field_simp [hden.ne']; ring
rw [hid]
have hsplit : 60 * K * n / d = 12 * K * n / d + 48 * K * n / d := by ring
rw [hsplit]
linarith
theorem thresholdCover_card_le {d K k : ℕ} {ρ : ℝ} (xplus xminus : V → ℕ)
(hd : 0 < d) (h72 : 72 * K ≤ d) (hk : k ≤ Fintype.card V)
(hρ : 0 < ρ) (h120 : 120 * (K : ℝ) / ρ ≤ d)
(hplus : (∑ v, xplus v) ≤ d * k)
(htotal : (∑ v, (xplus v + xminus v)) ≤ d * Fintype.card V)
(hside : ∀ v, d ≤ xplus v + 6 * K ∨ d ≤ xminus v + 6 * K) :
((thresholdCover d xplus).card : ℝ) ≤ (k : ℝ) + ρ * Fintype.card V := by
have hd0 : (0 : ℝ) < d := by exact_mod_cast hd
have h72' : 72 * (K : ℝ) ≤ d := by exact_mod_cast h72
calc
_ ≤ (d : ℝ) * k / ((d : ℝ) - 6 * K) + 48 * (K : ℝ) * Fintype.card V / d :=
thresholdCover_card_le_fractions xplus xminus hd h72 hplus htotal hside
_ ≤ (k : ℝ) + 60 * (K : ℝ) * Fintype.card V / d :=
cover_fraction_bound hd0 (Nat.cast_nonneg K) (Nat.cast_nonneg k)
(by exact_mod_cast hk) (by linarith)
_ ≤ (k : ℝ) + ρ * Fintype.card V :=
add_le_add (le_refl (k : ℝ)) (sixty_loss_div_le hρ hd0 (Nat.cast_nonneg K)
(Nat.cast_nonneg _) h120)
theorem longMatch_sum_lower {R P : ℕ} (S : Finset (Fin R)) (L : Fin R → ℕ)
{a : ℝ} (ha : 0 ≤ a) (hS : (R : ℝ) - P ≤ (S.card : ℝ))
(hL : ∀ j ∈ S, a ≤ (L j : ℝ)) :
((R : ℝ) - P) * a ≤ ∑ j, (L j : ℝ) := by
calc
_ ≤ (S.card : ℝ) * a := mul_le_mul_of_nonneg_right hS ha
_ = ∑ _j ∈ S, a := by simp
_ ≤ ∑ j ∈ S, (L j : ℝ) := Finset.sum_le_sum hL
_ ≤ ∑ j, (L j : ℝ) :=
Finset.sum_le_sum_of_subset_of_nonneg (Finset.subset_univ _) (by intros; positivity)
theorem thresholdCover_isCover (G : GraphInput) {d K P R : ℕ}
(xplus : G.Vertex → ℕ)
(Sleft Sright : G.Edge → Finset (Fin R))
(Lleft Lright : G.Edge → Fin R → ℕ)
(hd : 1 ≤ d) (h72 : 72 * K ≤ d) (hR : R = repetitions P G.n K)
(hSleft : ∀ e, (R : ℝ) - P ≤ ((Sleft e).card : ℝ))
(hSright : ∀ e, (R : ℝ) - P ≤ ((Sright e).card : ℝ))
(hLleft : ∀ e j, j ∈ Sleft e → d ≤ Lleft e j + xplus (G.left e) + 9 * K)
(hLright : ∀ e j, j ∈ Sright e → d ≤ Lright e j + xplus (G.right e) + 9 * K)
(hcapacity : ∀ e, (∑ j, Lleft e j) + (∑ j, Lright e j) ≤
d * R + 3 * G.n * K) :
G.IsCover (thresholdCover d xplus) := by
classical
let C := thresholdCover d xplus
have hd0 : (0 : ℝ) < d := by exact_mod_cast (Nat.lt_of_lt_of_le Nat.zero_lt_one hd)
have h72' : 72 * (K : ℝ) ≤ d := by exact_mod_cast h72
have hstrict : (d : ℝ) * R + 3 * (G.n : ℝ) * K <
2 * ((R : ℝ) - P) * (3 * (d : ℝ) / 4) := by
rw [hR]
exact edge_demand_exceeds_capacity P G.n K d hd
have hindex : ∀ e : G.Edge, G.left e ∈ C ∨ G.right e ∈ C := by
intro e
by_cases hv : G.left e ∈ C
· exact Or.inl hv
right
by_contra hw
have hxleft : (xplus (G.left e) : ℝ) ≤ (d : ℝ) / 8 := by
apply le_of_not_gt
simpa [C, thresholdCover] using hv
have hxright : (xplus (G.right e) : ℝ) ≤ (d : ℝ) / 8 := by
apply le_of_not_gt
simpa [C, thresholdCover] using hw
have hleft : ((R : ℝ) - P) * (3 * (d : ℝ) / 4) ≤
∑ j, (Lleft e j : ℝ) := by
apply longMatch_sum_lower _ _ (by positivity) (hSleft e)
intro j hj
have hmatch : (d : ℝ) ≤ (Lleft e j : ℝ) + xplus (G.left e) + 9 * K := by
exact_mod_cast hLleft e j hj
exact three_quarter_lower h72' hxleft (by linarith)
have hright : ((R : ℝ) - P) * (3 * (d : ℝ) / 4) ≤
∑ j, (Lright e j : ℝ) := by
apply longMatch_sum_lower _ _ (by positivity) (hSright e)
intro j hj
have hmatch : (d : ℝ) ≤ (Lright e j : ℝ) + xplus (G.right e) + 9 * K := by
exact_mod_cast hLright e j hj
exact three_quarter_lower h72' hxright (by linarith)
have hcap : (∑ j, (Lleft e j : ℝ)) + (∑ j, (Lright e j : ℝ)) ≤
(d : ℝ) * R + 3 * (G.n : ℝ) * K := by exact_mod_cast hcapacity e
linarith
intro e he
obtain ⟨i, hi, heq⟩ := List.mem_iff_getElem.mp he
have h := hindex ⟨i, hi⟩
change (G.edges[i]).1 ∈ C ∨ (G.edges[i]).2 ∈ C at h
rw [heq] at h
exact h
theorem thresholdCover_card_le_graph (G : GraphInput) {d K k : ℕ} {ρ : ℝ}
(xplus xminus : G.Vertex → ℕ)
(hd : 0 < d) (h72 : 72 * K ≤ d) (hk : k ≤ G.n)
(hρ : 0 < ρ) (h120 : 120 * (K : ℝ) / ρ ≤ d)
(hplus : (∑ v, xplus v) ≤ d * k)
(htotal : (∑ v, (xplus v + xminus v)) ≤ d * G.n)
(hside : ∀ v, d ≤ xplus v + 6 * K ∨ d ≤ xminus v + 6 * K) :
((thresholdCover d xplus).card : ℝ) ≤ (k : ℝ) + ρ * G.n := by
simpa only [Fintype.card_fin] using
thresholdCover_card_le xplus xminus hd h72
(by simpa only [Fintype.card_fin] using hk) hρ h120 hplus
(by simpa only [Fintype.card_fin] using htotal) hside
end BinPackingGap
end
namespace BinPackingGap
def completeFourGraph : GraphInput where
n := 4
edges := [(0, 1), (0, 2), (0, 3), (1, 2), (1, 3), (2, 3)]
ordered := by decide
distinct := by decide
theorem completeFourGraph_edge_pos : 0 < completeFourGraph.edges.length := by decide
theorem completeFourGraph_cover_card {C : Finset completeFourGraph.Vertex}
(hC : completeFourGraph.IsCover C) : 3 ≤ C.card := by
classical
change Finset (Fin 4) at C
change 3 ≤ C.card
change ∀ e : Fin 4 × Fin 4,
e ∈ [(0, 1), (0, 2), (0, 3), (1, 2), (1, 3), (2, 3)] →
e.1 ∈ C ∨ e.2 ∈ C at hC
have h01 : (0 : Fin 4) ∈ C ∨ (1 : Fin 4) ∈ C :=
hC ((0 : Fin 4), (1 : Fin 4)) (by decide)
have h02 : (0 : Fin 4) ∈ C ∨ (2 : Fin 4) ∈ C :=
hC ((0 : Fin 4), (2 : Fin 4)) (by decide)
have h03 : (0 : Fin 4) ∈ C ∨ (3 : Fin 4) ∈ C :=
hC ((0 : Fin 4), (3 : Fin 4)) (by decide)
have h12 : (1 : Fin 4) ∈ C ∨ (2 : Fin 4) ∈ C :=
hC ((1 : Fin 4), (2 : Fin 4)) (by decide)
have h13 : (1 : Fin 4) ∈ C ∨ (3 : Fin 4) ∈ C :=
hC ((1 : Fin 4), (3 : Fin 4)) (by decide)
have h23 : (2 : Fin 4) ∈ C ∨ (3 : Fin 4) ∈ C :=
hC ((2 : Fin 4), (3 : Fin 4)) (by decide)
have hsmall : (Finset.univ \ C).card ≤ 1 := by
apply Finset.card_le_one.mpr
intro x hx y hy
have hxC : x ∉ C := (Finset.mem_sdiff.mp hx).2
have hyC : y ∉ C := (Finset.mem_sdiff.mp hy).2
fin_cases x <;> fin_cases y <;> simp_all
have htotal : (Finset.univ \ C).card + C.card = 4 := by
simpa only [Finset.card_univ, Fintype.card_fin, completeFourGraph] using
Finset.card_sdiff_add_card_eq_card (Finset.subset_univ C)
omega
theorem completeFourGraph_cover_three : completeFourGraph.CoverAtMost 3 := by
change ∃ C : Finset (Fin 4),
(∀ e : Fin 4 × Fin 4,
e ∈ [(0, 1), (0, 2), (0, 3), (1, 2), (1, 3), (2, 3)] →
e.1 ∈ C ∨ e.2 ∈ C) ∧ C.card ≤ 3
exact ⟨{0, 1, 2}, by decide, by decide⟩
theorem completeFourGraph_no_small_cover :
¬ ∃ C : Finset completeFourGraph.Vertex,
completeFourGraph.IsCover C ∧
(C.card : ℝ) ≤ 2 + (1 / 8 : ℝ) * completeFourGraph.n := by
rintro ⟨C, hC, hcard⟩
have hthree : (3 : ℝ) ≤ C.card := by exact_mod_cast completeFourGraph_cover_card hC
norm_num [completeFourGraph] at hcard
linarith
end BinPackingGap
end
end OAI