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Diff — Birthday problem

Revision #3039 → #3563 · back to history

modifiedBirthday problem5818e3c78edc
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noteNo formalization of the birthday problem appears in Mathlib (grep for 'Birthday' returns nothing).No formalization of the birthday problem appears in Mathlib (grep for 'birthday' returns no hits).
modifiedBirthday paradox (23 people)b776a4744123
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noteThe 23-person threshold is not proved in Mathlib.The 23-person 50% threshold is not proved in Mathlib.
addedBirthday attack0ad3261afa6e
modifiedEvents A and B8a96a2ec42b0
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noteThese birthday events are not defined in Mathlib.The specific birthday events A and B are not defined in Mathlib.
modifiedComplementary probability relation1b6cde6d1e6b
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mathlib.moduleMathlib.MeasureTheory.Measure.MeasureSpaceMathlib.MeasureTheory.Measure.Typeclasses.Probability
noteGeneral complement-probability identities exist in Mathlib but not specialized to the birthday events.The general complement-probability identity `μ sᶜ = 1 - μ s` is in Mathlib, but not specialized to the birthday events.
modifiedGeneral formula for p(n)66d8cafecb60
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noteMathlib counts injections as descFactorial (the numerator of the no-collision probability) but does not state the birthday probability formula.Mathlib counts injections via `Fintype.card_embedding_eq` (the numerator of the no-collision probability) but does not state the birthday probability formula.
modifiedPigeonhole boundfab3b419e178
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mathlib.declFintype.card_embedding_eq_of_infiniteFinset.exists_ne_map_eq_of_card_lt_of_maps_to
mathlib.moduleMathlib.Data.Fintype.CardEmbeddingMathlib.Data.Finset.Basic
noteThe pigeonhole principle is formalized in Mathlib (e.g. `Finset.exists_ne_map_eq_of_card_lt_of_maps_to`), but the birthday-specific consequence is not stated.Mathlib formalizes the pigeonhole principle in general (e.g. `Finset.exists_ne_map_eq_of_card_lt_of_maps_to`), but the birthday-specific consequence is not stated.
provenanceaiai-moderated
modifiedTaylor series first-order approximation2687010eb411
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mathlib.moduleMathlib.Analysis.SpecialFunctions.ExpMathlib.Analysis.Complex.Exponential
noteMathlib has the inequality `1 + x ≤ exp x` and exponential Taylor series; the birthday-context use is not stated.Mathlib has the inequality `x + 1 ≤ exp x` as `Real.add_one_le_exp`; its birthday-context use is not stated.
modifiedSimple exponentiation approximation3e04cdf156d7
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noteThis independence-based approximation is not formalized.This independence-based birthday approximation is not formalized.
modifiedPoisson approximation37325d006cbd
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noteMathlib has the Poisson distribution but not the Poisson approximation to the binomial for birthdays.Mathlib has the Poisson distribution but no Poisson-to-binomial approximation for the birthday setup.
modified23 people suffice0e21026f6499
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noteNot formalized.Not formalized in Mathlib.
modifiedGeneralized birthday problem n(d)6a65572cffd9
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noteNot formalized.Not formalized in Mathlib.
modifiedBounds on n(d)a87b5a5e7c9c
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noteNot formalized.Not formalized in Mathlib.
modifiedAsymptotic optimality of boundsd75a0d88f88e
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noteNot formalized.Not formalized in Mathlib.
modifiedFormula holds for 73% of integers9c3198e2f74b
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noteNot formalized.Not formalized in Mathlib.
modifiedFormula holds for almost all d944eeb674238
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noteNot formalized.Not formalized in Mathlib.
modifiedConjecture with counterexamplesc07049edba52
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noteNot formalized.Not formalized in Mathlib.
modifiedConjectured formula for all d28b5b818d90a
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noteNot formalized.Not formalized in Mathlib.
modified3 and 4 person sharing thresholds32bebcbc9b20
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noteNot formalized.Not formalized in Mathlib.
modifiedStrong birthday problem6b714dfcc5be
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noteNot formalized.Not formalized in Mathlib.
modifiedCollision probability p(n;d)7c3e162b8bc1
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noteNot formalized.Not formalized in Mathlib.
modifiedHash collision expected count4b57ea5c5ea7
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noteNot formalized.Not formalized in Mathlib.
modifiedProbability of exactly one matching pair24f40229a4b0
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noteNot formalized.Not formalized in Mathlib.
modifiedMaximum of unique-match probabilityfd9faba38b8c
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noteNot formalized.Not formalized in Mathlib.
modifiedTwo-types generalization probabilityb782f96aa28b
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mathlib.declNat.stirlingSecond
mathlib.match_kindgeneralization
mathlib.moduleMathlib.Combinatorics.Enumerative.Stirling
noteNot formalized.Mathlib defines Stirling numbers of the second kind as `Nat.stirlingSecond`, which appear in the closed form, but not the two-types birthday probability itself.
statusnot_formalizedpartial
modifiedNon-uniqueness of m+n solution00f7afb7c005
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noteNot formalized.Not formalized in Mathlib.
modifiedFirst match position7f19309ea3fe
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noteNot formalized.Not formalized in Mathlib.
modifiedSame birthday as you probability089ef412b59c
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noteNot formalized.Not formalized in Mathlib.
modified253 people for 50% match with you85a5a8502a78
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noteNot formalized.Not formalized in Mathlib.
modifiedExpected number with shared birthday21530b4f5258
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noteNot formalized.Not formalized in Mathlib.
modifiedNear matches generalizationac4130598dc4
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noteNot formalized.Not formalized in Mathlib.
modifiedSeven people within a week76950721b174
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noteNot formalized.Not formalized in Mathlib.
modifiedExpected number of distinct birthdays5a0176cae911
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noteNot formalized.Not formalized in Mathlib.
modifiedExpected days with at least two birthdaysa3dcb6ef3bb4
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noteNot formalized.Not formalized in Mathlib.
modifiedExpected number of repeats1bc7f795cc15
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noteNot formalized.Not formalized in Mathlib.
modifiedAverage number of people Q(M)8bf58c8ab7d5
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noteNot formalized.Not formalized in Mathlib.
modifiedRamanujan asymptotic expansion7371bb6f9fa9
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noteNot formalized.Not formalized in Mathlib.
modifiedAverage of 24.61659 people7af82e38b318
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noteNot formalized.Not formalized in Mathlib.
modifiedIndicator variable analysisb596c504f230
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noteNot formalized.Not formalized in Mathlib.
modifiedFIFA World Cup 2014 squadsfb653f9e0969
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noteNot formalized.Not formalized in Mathlib.
modifiedPartition problem answer is 23f0a38e098706
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noteNot formalized.Not formalized in Mathlib.