OAI/Combinatorics/PerfectMatching/Coupling.lean

GitHub source file

17 declarations, 0 contain sorry, 0 declared as axioms

Finite pushforwards and couplings with a prescribed common marginal.

  1. def OAI.MatchingEntropy.fiberMass line 17

    Source documentation

    Finite pushforward weights.

    def fiberMass {A C : Type*} [Fintype A] [DecidableEq C]
        (p : A → ℝ) (f : A → C) (c : C) : ℝ := ∑ a, if f a = c then p a else 0
  2. theorem OAI.MatchingEntropy.fiberMass_nonneg line 20
  3. theorem OAI.MatchingEntropy.le_fiberMass_self line 27
  4. def OAI.MatchingEntropy.jointLaw line 36

    Source documentation

    The explicit cut-choice coupling. Only equal choices receive mass.

    def jointLaw {A B C : Type*} [Fintype A] [Fintype B] [DecidableEq C]
        (p : A → ℝ) (q : B → ℝ) (f : A → C) (g : B → C) (z : A × B) : ℝ :=
    …
  5. theorem OAI.MatchingEntropy.jointLaw_nonneg line 40
  6. theorem OAI.MatchingEntropy.jointLaw_first line 48
  7. theorem OAI.MatchingEntropy.jointLaw_second line 68
  8. theorem OAI.MatchingEntropy.jointLaw_mem_simplex line 88
  9. theorem OAI.MatchingEntropy.sum_subtype_supported line 97
  10. theorem OAI.MatchingEntropy.compatible_jointLaw_mem_simplex line 107

    Source documentation

    No mass is lost in retaining only compatible pairs.

    theorem compatible_jointLaw_mem_simplex {A B C : Type*} [Fintype A] [Fintype B] [DecidableEq C]
        {p : A → ℝ} {q : B → ℝ} (hp : p ∈ probabilitySimplex A) (hq : q ∈ probabilitySimplex B)
        (f : A → C) (g : B → C) (hcompat : ∀ c, fiberMass p f c = fiberMass q g c) :
        (fun z : {z : A × B // f z.1=g z.2} => jointLaw p q f g z.val) ∈
          probabilitySimplex {z : A × B // f z.1=g z.2} := by
    …

    Mentions: OAI.MatchingEntropy.probabilitySimplex, OAI.MatchingEntropy.fiberMass, OAI.MatchingEntropy.jointLaw

  11. theorem OAI.MatchingEntropy.fiberMass_sum line 117
  12. theorem OAI.MatchingEntropy.fiberMass_expect line 123
  13. theorem OAI.MatchingEntropy.fiberMass_mem_simplex line 134
  14. theorem OAI.MatchingEntropy.jointLaw_expect_first line 139
  15. theorem OAI.MatchingEntropy.jointLaw_expect_second line 146
  16. theorem OAI.MatchingEntropy.compatible_jointLaw_expect_first line 153
  17. theorem OAI.MatchingEntropy.compatible_jointLaw_expect_second line 163