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Question 692: Nonsufficiency, Zero Mass, Identity and Constant Statistics Need Separate Checks

On this page
  1. Original question and givens
  2. Definition and scope
  3. Step-by-step derivation
  4. Reverse checks
  5. Result
  6. This question review and source binding

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P1000-0692 · q-20261015-advance-20261116-r05-finite-sufficient-statistic-0092

Original question and givens

Use complete theta labels=[a16, b16], samples=[160, 161, 162, 163], aligned exact probability rows=[[[3, 5], [1, 10], [1, 5], [1, 10]], [[1, 10], [2, 5], [1, 10], [2, 5]]] and total statistic=[0, 1, 0, 1]. Each theta law is normalized. Fibers partition the full sample carrier, retaining zero-mass cells. Mode=nonsufficient. Give (mode, fiber_invariance_rows, sufficient, zero_mass_cells, nonsufficiency_witness_or_null, injective_statistic, constant_statistic, theta_laws_equal, constant_equivalence_if_applicable, factorization_or_quality_claim, boundary).

  • G001 — Use complete theta labels=[a16, b16], samples=[160, 161, 162, 163], aligned exact probability rows=[[[3, 5], [1, 10], [1, 5], [1, 10]], [[1, 10], [2, 5], [1, 10], [2, 5]]] and total statistic=[0, 1, 0, 1]. Each theta law is normalized. Fibers partition the full sample carrier, retaining zero-mass cells. Mode=nonsufficient. Give (mode, fiber_invariance_rows, sufficient, zero_mass_cells, nonsufficiency_witness_or_null, injective_statistic, constant_statistic, theta_laws_equal, constant_equivalence_if_applicable, factorization_or_quality_claim, boundary).

Definition and scope

One positive-mass fiber with differing conditional laws refutes sufficiency. An injective statistic is sufficient; a constant one exactly when all laws agree; zero-mass cells stay null.

Step-by-step derivation

S001 · implies

Before

Θ=[a16, b16]; Ω=[160, 161, 162, 163]

After

[[3/5, 1/10, 1/5, 1/10], [1/10, 2/5, 1/10, 2/5]]

Conditions: none

Each row is one parameter law and each column an outcome; reorder probabilities together with labels.

Step identifiers and dependencies

Rule: full_parametric_model · Uses: G001

S002 · calculation

Before

P_a16(Ω) := sum(3/5, 1/10, 1/5, 1/10)

After

P_a16(Ω) = 1

Conditions: none

Check this law's complete total mass first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

P_b16(Ω) := sum(1/10, 2/5, 1/10, 2/5)

After

P_b16(Ω) = 1

Conditions: none

Check this law's complete total mass first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · implies

Before

sample=160

After

T(160)=0

Conditions: none

Every sample has exactly one statistic value.

Step identifiers and dependencies

Rule: total_statistic_map · Uses: G001, S003

S005 · implies

Before

sample=161

After

T(161)=1

Conditions: none

Every sample has exactly one statistic value.

Step identifiers and dependencies

Rule: total_statistic_map · Uses: G001, S004

S006 · implies

Before

sample=162

After

T(162)=0

Conditions: none

Every sample has exactly one statistic value.

Step identifiers and dependencies

Rule: total_statistic_map · Uses: G001, S005

S007 · implies

Before

sample=163

After

T(163)=1

Conditions: none

Every sample has exactly one statistic value.

Step identifiers and dependencies

Rule: total_statistic_map · Uses: G001, S006

S008 · implies

Before

[(160, 0), (161, 1), (162, 0), (163, 1)]

After

fibers=[[0, [160, 162]], [1, [161, 163]]]

Conditions: none

Grouping by value produces disjoint fibers whose union is the complete carrier.

Step identifiers and dependencies

Rule: fiber_partition · Uses: G001, S007

S009 · calculation

Before

P_a16(T=0) := sum(3/5, 1/5)

After

P_a16(T=0) = 4/5

Conditions: none

First compute the conditioning event's full mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

P_a16(160|T=0) := div(3/5, 4/5)

After

P_a16(160|T=0) = 3/4

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

reconstruct atom 160 under a16 := mul(3/4, 4/5)

After

reconstruct atom 160 under a16 = 3/5

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · calculation

Before

P_a16(162|T=0) := div(1/5, 4/5)

After

P_a16(162|T=0) = 1/4

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

reconstruct atom 162 under a16 := mul(1/4, 4/5)

After

reconstruct atom 162 under a16 = 1/5

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · calculation

Before

conditional total (a16,0) := sum(3/4, 1/4)

After

conditional total (a16,0) = 1

Conditions: none

The complete conditional law must have total mass1.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · calculation

Before

P_a16(T=1) := sum(1/10, 1/10)

After

P_a16(T=1) = 1/5

Conditions: none

First compute the conditioning event's full mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · calculation

Before

P_a16(161|T=1) := div(1/10, 1/5)

After

P_a16(161|T=1) = 1/2

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S015

S017 · calculation

Before

reconstruct atom 161 under a16 := mul(1/2, 1/5)

After

reconstruct atom 161 under a16 = 1/10

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · calculation

Before

P_a16(163|T=1) := div(1/10, 1/5)

After

P_a16(163|T=1) = 1/2

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S017

S019 · calculation

Before

reconstruct atom 163 under a16 := mul(1/2, 1/5)

After

reconstruct atom 163 under a16 = 1/10

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · calculation

Before

conditional total (a16,1) := sum(1/2, 1/2)

After

conditional total (a16,1) = 1

Conditions: none

The complete conditional law must have total mass1.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S019

S021 · calculation

Before

P_b16(T=0) := sum(1/10, 1/10)

After

P_b16(T=0) = 1/5

Conditions: none

First compute the conditioning event's full mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S020

S022 · calculation

Before

P_b16(160|T=0) := div(1/10, 1/5)

After

P_b16(160|T=0) = 1/2

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S021

S023 · calculation

Before

reconstruct atom 160 under b16 := mul(1/2, 1/5)

After

reconstruct atom 160 under b16 = 1/10

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S022

S024 · calculation

Before

P_b16(162|T=0) := div(1/10, 1/5)

After

P_b16(162|T=0) = 1/2

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S023

S025 · calculation

Before

reconstruct atom 162 under b16 := mul(1/2, 1/5)

After

reconstruct atom 162 under b16 = 1/10

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S024

S026 · calculation

Before

conditional total (b16,0) := sum(1/2, 1/2)

After

conditional total (b16,0) = 1

Conditions: none

The complete conditional law must have total mass1.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S025

S027 · calculation

Before

P_b16(T=1) := sum(2/5, 2/5)

After

P_b16(T=1) = 4/5

Conditions: none

First compute the conditioning event's full mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S026

S028 · calculation

Before

P_b16(161|T=1) := div(2/5, 4/5)

After

P_b16(161|T=1) = 1/2

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S027

S029 · calculation

Before

reconstruct atom 161 under b16 := mul(1/2, 4/5)

After

reconstruct atom 161 under b16 = 2/5

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S028

S030 · calculation

Before

P_b16(163|T=1) := div(2/5, 4/5)

After

P_b16(163|T=1) = 1/2

Conditions: none

Divide the same law's atom mass by its positive fiber mass.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S029

S031 · calculation

Before

reconstruct atom 163 under b16 := mul(1/2, 4/5)

After

reconstruct atom 163 under b16 = 2/5

Conditions: none

Multiply by fiber mass to check the original atom probability.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S030

S032 · calculation

Before

conditional total (b16,1) := sum(1/2, 1/2)

After

conditional total (b16,1) = 1

Conditions: none

The complete conditional law must have total mass1.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S031

S033 · implies

Before

valid positive-mass laws for T=0: [[a16, [[160, 3/4], [162, 1/4]]], [b16, [[160, 1/2], [162, 1/2]]]]

After

parameter-invariant: No

Conditions: none

Compare full defined conditional laws; parameter invariance requires every sample probability to agree.

Step identifiers and dependencies

Rule: conditional_law_comparison · Uses: G001, S032

S034 · implies

Before

valid positive-mass laws for T=1: [[a16, [[161, 1/2], [163, 1/2]]], [b16, [[161, 1/2], [163, 1/2]]]]

After

parameter-invariant: Yes

Conditions: none

Compare full defined conditional laws; parameter invariance requires every sample probability to agree.

Step identifiers and dependencies

Rule: conditional_law_comparison · Uses: G001, S033

S035 · implies

Before

[[0, [[a16, [[160, 3/4], [162, 1/4]]], [b16, [[160, 1/2], [162, 1/2]]]], No], [1, [[a16, [[161, 1/2], [163, 1/2]]], [b16, [[161, 1/2], [163, 1/2]]]], Yes]]

After

all fibers invariant: No

Conditions: none

Sufficiency under this finite contract requires every fiber to pass, not just one.

Step identifiers and dependencies

Rule: finite_sufficiency_definition · Uses: G001, S034

S036 · implies

Before

[0, [[a16, [[160, 3/4], [162, 1/4]]], [b16, [[160, 1/2], [162, 1/2]]]], No]

After

one positive-mass conditional-law disagreement refutes sufficiency

Conditions: none

Exhibit the conditional probability disagreement on one common fiber, rather than infer nonsufficiency from a name.

Step identifiers and dependencies

Rule: nonsufficiency_witness · Uses: G001, S035

Reverse checks

  • S036 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S035 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S034 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S033 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S032 · premise_and_result_audit — Recompute conditional total (b16,1) with exact rational arithmetic, not rounded decimals.
  • S031 · premise_and_result_audit — Recompute reconstruct atom 163 under b16 with exact rational arithmetic, not rounded decimals.
  • S030 · premise_and_result_audit — Recompute P_b16(163|T=1) with exact rational arithmetic, not rounded decimals.
  • S029 · premise_and_result_audit — Recompute reconstruct atom 161 under b16 with exact rational arithmetic, not rounded decimals.
  • S028 · premise_and_result_audit — Recompute P_b16(161|T=1) with exact rational arithmetic, not rounded decimals.
  • S027 · premise_and_result_audit — Recompute P_b16(T=1) with exact rational arithmetic, not rounded decimals.
  • S026 · premise_and_result_audit — Recompute conditional total (b16,0) with exact rational arithmetic, not rounded decimals.
  • S025 · premise_and_result_audit — Recompute reconstruct atom 162 under b16 with exact rational arithmetic, not rounded decimals.
  • S024 · premise_and_result_audit — Recompute P_b16(162|T=0) with exact rational arithmetic, not rounded decimals.
  • S023 · premise_and_result_audit — Recompute reconstruct atom 160 under b16 with exact rational arithmetic, not rounded decimals.
  • S022 · premise_and_result_audit — Recompute P_b16(160|T=0) with exact rational arithmetic, not rounded decimals.
  • S021 · premise_and_result_audit — Recompute P_b16(T=0) with exact rational arithmetic, not rounded decimals.
  • S020 · premise_and_result_audit — Recompute conditional total (a16,1) with exact rational arithmetic, not rounded decimals.
  • S019 · premise_and_result_audit — Recompute reconstruct atom 163 under a16 with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Recompute P_a16(163|T=1) with exact rational arithmetic, not rounded decimals.
  • S017 · premise_and_result_audit — Recompute reconstruct atom 161 under a16 with exact rational arithmetic, not rounded decimals.
  • S016 · premise_and_result_audit — Recompute P_a16(161|T=1) with exact rational arithmetic, not rounded decimals.
  • S015 · premise_and_result_audit — Recompute P_a16(T=1) with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Recompute conditional total (a16,0) with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute reconstruct atom 162 under a16 with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute P_a16(162|T=0) with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute reconstruct atom 160 under a16 with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute P_a16(160|T=0) with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute P_a16(T=0) with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S007 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S006 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S005 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S004 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.
  • S003 · premise_and_result_audit — Recompute P_b16(Ω) with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute P_a16(Ω) with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Retain every parameter and sample label; distinguish null, empty tables, zero distributions and tied optima.

Result

(nonsufficient, [[0, [[a16, [[160, 3/4], [162, 1/4]]], [b16, [[160, 1/2], [162, 1/2]]]], No], [1, [[a16, [[161, 1/2], [163, 1/2]]], [b16, [[161, 1/2], [163, 1/2]]]], Yes]], No, [], [0, [[a16, [[160, 3/4], [162, 1/4]]], [b16, [[160, 1/2], [162, 1/2]]]], No], No, No, No, Yes, No, identity_is_sufficient_constant_is_sufficient_exactly_when_theta_laws_match_no_factorization_or_estimator_quality_claim)

The full substitutions and premise audits recover the original answer, retaining its field order and verdict meanings.

This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.

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  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: 8f8f04fe527142b59f2288fc98b4ee17d3b27d760ea6d9523fe326596e8bf373
  • candidate record SHA-256: e0ca6b301a58438a2b4ffea81db68dc08157d010c57919aa1ca82610ffef6ffa
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  • Lean: NOT_RUN · human review: NOT_PERFORMED
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