OAI/Probability/MatroidSecretary/Secretary/ConditionalLaw.lean

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15 declarations, 0 contain sorry, 0 declared as axioms

Exact normalization, support, and joint-law identities for finite conditional seed reconstruction. This is supporting work for cor:secretary; it does not assume a prefix law or supply the online secretary construction by itself.

  1. theorem OAI.MatroidProphet.Secretary.fiberMass_nonneg line 22
  2. theorem OAI.MatroidProphet.Secretary.le_fiberMass line 31
  3. theorem OAI.MatroidProphet.Secretary.source_zero_of_fiberMass_zero line 40
  4. theorem OAI.MatroidProphet.Secretary.fiberKernel_nonneg line 47
  5. theorem OAI.MatroidProphet.Secretary.fiberKernel_sum line 57
  6. theorem OAI.MatroidProphet.Secretary.fiberKernel_support line 71
  7. theorem OAI.MatroidProphet.Secretary.fiberMass_mul_fiberKernel line 78

    Source documentation

    The exact joint law, including observations of zero source probability.

    theorem fiberMass_mul_fiberKernel (p : α → ℝ) (hp : ∀ a, 0 ≤ p a)
        (f : α → β) (fallback : α) (b : β) (a : α) :
        fiberMass p f b * fiberKernel p f fallback b a =
          if f a = b then p a else 0 := by
    …

    Mentions: OAI.MatroidProphet.Secretary.fiberMass, OAI.MatroidProphet.Secretary.fiberKernel

  8. theorem OAI.MatroidProphet.Secretary.fiberMass_sum line 94
  9. theorem OAI.MatroidProphet.Secretary.fiberKernel_joint_expectation line 104

    Source documentation

    Reconstruction preserves the full joint distribution of observation and seed. The test function may depend on unused source coordinates and on the observation.

    theorem fiberKernel_joint_expectation (p : α → ℝ) (hp : ∀ a, 0 ≤ p a)
        (f : α → β) (fallback : α) (g : β → α → ℝ) :
        (∑ b, fiberMass p f b * (∑ a, fiberKernel p f fallback b a * g b a)) =
          ∑ a, p a * g (f a) a := by
    …

    Mentions: OAI.MatroidProphet.Secretary.fiberMass, OAI.MatroidProphet.Secretary.fiberKernel

  10. theorem OAI.MatroidProphet.Secretary.fiberKernel_marginal line 114
  11. def OAI.MatroidProphet.Secretary.fiberPMF line 121

    Source documentation

    A bona fide conditional probability mass function on the complete seed.

    noncomputable def fiberPMF (p : α → ℝ) (hp : ∀ a, 0 ≤ p a)
        (f : α → β) (fallback : α) (b : β) : PMF α :=
    …
  12. theorem OAI.MatroidProphet.Secretary.fiberPMF_apply line 129
  13. def OAI.MatroidProphet.Secretary.fiberMarginalPMF line 135

    Source documentation

    The observation marginal as an actual PMF, with its normalization proved.

    noncomputable def fiberMarginalPMF (p : α → ℝ) (hp : ∀ a, 0 ≤ p a)
        (hpsum : ∑ a, p a = 1) (f : α → β) : PMF β :=
    …
  14. theorem OAI.MatroidProphet.Secretary.fiberMarginalPMF_apply line 142
  15. theorem OAI.MatroidProphet.Secretary.fiberPMF_joint_atom line 147