OAI/Probability/MatroidSecretary/Secretary/ReplayFacts.lean

GitHub source file

10 declarations, 0 contain sorry, 0 declared as axioms

Deterministic replay for the secretary transport

This optional supplement uses a distinct namespace so it can coexist with the canonical SecretaryReplay implementation without duplicate declaration names.

These lemmas concern the replay step in the proof of cor:secretary in the pinned sections/secretary.tex. They do not assert or assume the random-prefix law. The latter is a separate probability obligation. A reconstructed seed may be any function of the secretary seed and observed prefix: all the results below hold pointwise for every seed and every completed arrival permutation.

  1. lemma OAI.MatroidProphet.SecretaryReplaySupplement.glue_eq_of_agree line 25

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    Agreement on the sacrificed labels is the exact information needed to replay an actual fixed vector. Values supplied outside that mask are irrelevant.

    lemma glue_eq_of_agree {n : ℕ} (mask : Finset (Fin n)) (s w : Weights n)
        (hs : ∀ e ∈ mask, s e = w e) : glue mask s w = w := by
    …

    Mentions: OAI.MatroidProphet.Weights, OAI.MatroidProphet.glue

  2. lemma OAI.MatroidProphet.SecretaryReplaySupplement.observed_agrees line 33
  3. lemma OAI.MatroidProphet.SecretaryReplaySupplement.history_replay line 41

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    The actual current and past label--weight pairs, including rejected prefix arrivals, are passed to the source core unchanged.

    lemma history_replay {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (s w : Weights n) (hs : ∀ e ∈ A.mask r, s e = w e)
        (π : ArrivalOrder n) (k : Fin n) :
        simulationHistory A r s (history w π k) = history w π k := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.simulationHistory, OAI.MatroidProphet.history

  4. theorem OAI.MatroidProphet.SecretaryReplaySupplement.acceptedThrough_replay line 48

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    Exact accepted-set identity at every time, not just equality of total reward.

    theorem acceptedThrough_replay {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (s w : Weights n) (hs : ∀ e ∈ A.mask r, s e = w e)
        (π : ArrivalOrder n) (t : ℕ) :
        acceptedThrough (sampleSimulation A) r s w π t =
          hiddenAcceptedThrough A r w π t := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.acceptedThrough, OAI.MatroidProphet.sampleSimulation, OAI.MatroidProphet.hiddenAcceptedThrough

  5. theorem OAI.MatroidProphet.SecretaryReplaySupplement.reward_replay line 56

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    Replay never replaces a realized payoff by a sampled or auxiliary value.

    theorem reward_replay {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (s w : Weights n) (hs : ∀ e ∈ A.mask r, s e = w e)
        (π : ArrivalOrder n) :
        reward (sampleSimulation A) r s w π = hiddenReward A r w π := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.reward, OAI.MatroidProphet.sampleSimulation, OAI.MatroidProphet.hiddenReward

  6. theorem OAI.MatroidProphet.SecretaryReplaySupplement.observed_replay line 63

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    Only the revealed vector is needed for the initial observation.

    theorem observed_replay {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (w : Weights n) (π : ArrivalOrder n) (t : ℕ) :
        acceptedThrough (sampleSimulation A) r (observed A r w) w π t =
          hiddenAcceptedThrough A r w π t :=
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.acceptedThrough, OAI.MatroidProphet.sampleSimulation, OAI.MatroidProphet.observed, OAI.MatroidProphet.hiddenAcceptedThrough

  7. theorem OAI.MatroidProphet.SecretaryReplaySupplement.prefix_rejected line 71

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    If the mask is exactly the observed prefix set, no prefix label is accepted. The bound includes both zero-length and full-length prefixes.

    theorem prefix_rejected {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (s w : Weights n) (π : ArrivalOrder n) (K : ℕ)
        (hmask : ∀ e, e ∈ A.mask r ↔ (π.symm e).val < K) :
        acceptedThrough (sampleSimulation A) r s w π K = ∅ := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.acceptedThrough, OAI.MatroidProphet.sampleSimulation

  8. theorem OAI.MatroidProphet.SecretaryReplaySupplement.accepted_after_prefix line 83

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    The prefix is still excluded at all later times.

    theorem accepted_after_prefix {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (s w : Weights n) (π : ArrivalOrder n) (K t : ℕ)
        (hmask : ∀ e, e ∈ A.mask r ↔ (π.symm e).val < K)
        {e : Fin n} (he : e ∈ acceptedThrough (sampleSimulation A) r s w π t) :
        K ≤ (π.symm e).val := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.acceptedThrough, OAI.MatroidProphet.sampleSimulation

  9. theorem OAI.MatroidProphet.SecretaryReplaySupplement.worstReward_le_replay line 94

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    An arbitrary suffix order, even one knowing all unused seed coordinates, cannot defeat the pointwise minimum over completed permutations.

    theorem worstReward_le_replay {n bits : ℕ} (A : HiddenRule n bits) (r : Seed bits)
        (s w : Weights n) (hs : ∀ e ∈ A.mask r, s e = w e)
        (π : ArrivalOrder n) :
        hiddenWorstReward A w r ≤ reward (sampleSimulation A) r s w π := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Seed, OAI.MatroidProphet.Weights, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.hiddenWorstReward, OAI.MatroidProphet.reward, OAI.MatroidProphet.sampleSimulation

  10. theorem OAI.MatroidProphet.SecretaryReplaySupplement.feasible_replay line 103

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    Every-prefix matroid feasibility transfers without a condition on the suffix adversary or on weights assigned outside the observation mask.

    theorem feasible_replay {n bits : ℕ} (M : Matroid (Fin n)) (A : HiddenRule n bits)
        (hA : ∀ (w : Weights n), (∀ e, 0 ≤ w e) →
          ∀ (r : Seed bits) (π : ArrivalOrder n) (t : ℕ),
            M.Indep (hiddenAcceptedThrough A r w π t : Set (Fin n)))
        (r : Seed bits) (s w : Weights n) (hw : ∀ e, 0 ≤ w e)
        (hs : ∀ e ∈ A.mask r, s e = w e) (π : ArrivalOrder n) (t : ℕ) :
        M.Indep (acceptedThrough (sampleSimulation A) r s w π t : Set (Fin n)) := by
    …

    Mentions: OAI.MatroidProphet.HiddenRule, OAI.MatroidProphet.Weights, OAI.MatroidProphet.Seed, OAI.MatroidProphet.ArrivalOrder, OAI.MatroidProphet.hiddenAcceptedThrough, OAI.MatroidProphet.acceptedThrough, OAI.MatroidProphet.sampleSimulation