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Question 14090: Keep Verified Independence and Zero Covariance Distinct

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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R0027-14090 · q-20261014-advance-20261028-r06-random-variable-independence-0090

Original question and givens

Use the complete joint grid with original x_values=[2, 27], y_values=[-3, 34], and aligned row-by-column exact masses=[[8/49, 6/49], [20/49, 15/49]]. Value labels must be distinct in each nonempty list, all masses nonnegative and their total exactly 1. Preserve grid order and zero masses; all marginals, events and moments use this same law. Two-variable independence requires factorization for every grid pair; it implies neither identical distribution, IID, Markov behavior nor larger-family mutual independence. Use exact reduced rational outputs with positive denominators; omit /1 for integers. Give (independent?,E_X,E_Y,E_XY,covariance,implication_pass,boundary=zero_covariance_converse_not_claimed). Despite the source field name, implication_pass is the conjunction of both verified independence and zero covariance in this protocol, not a truth value of material implication.

  • G001 — Use the complete joint grid with original x_values=[2, 27], y_values=[-3, 34], and aligned row-by-column exact masses=[[8/49, 6/49], [20/49, 15/49]]. Value labels must be distinct in each nonempty list, all masses nonnegative and their total exactly 1. Preserve grid order and zero masses; all marginals, events and moments use this same law. Two-variable independence requires factorization for every grid pair; it implies neither identical distribution, IID, Markov behavior nor larger-family mutual independence. Use exact reduced rational outputs with positive denominators; omit /1 for integers. Give (independent?,E_X,E_Y,E_XY,covariance,implication_pass,boundary=zero_covariance_converse_not_claimed). Despite the source field name, implication_pass is the conjunction of both verified independence and zero covariance in this protocol, not a truth value of material implication.

Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.

Step-by-step derivation

S001 · calculation

Before

joint grid model whole mass sum := sum(8/49, 6/49, 20/49, 15/49)

After

joint grid model whole mass sum = 1

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001

S002 · implies

Before

joint grid model:raw aligned masses=[[8, 49], [6, 49], [20, 49], [15, 49]]

After

normalized masses=[8/49, 6/49, 20/49, 15/49];nonnegative=Yes;total=1

Conditions: none

First qualify nonnegativity and exact unit total on one complete finite probability model.Retain zero-mass atoms;do not assume uniformity or substitute another model.

Step identifiers and dependencies

Rule: whole_finite_probability_law_not_uniform_assumption · Uses: G001, S001

S003 · implies

Before

original x row labels=[2, 27];original y column labels=[-3, 34]

After

normalized aligned row-by-column joint grid=[[8/49, 6/49], [20/49, 15/49]]

Conditions: none

Each value list is distinct but need not be numerically sorted.Pair every mass with its original row/column,including zero cells;sorting values must not misalign the grid.

Step identifiers and dependencies

Rule: RV_joint_grid_original_order_not_value_sort · Uses: G001, S002

S004 · calculation

Before

X row0 marginal := sum(8/49, 6/49)

After

X row0 marginal = 2/7

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

X row1 marginal := sum(20/49, 15/49)

After

X row1 marginal = 5/7

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Y column0 marginal := sum(8/49, 20/49)

After

Y column0 marginal = 4/7

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

Y column1 marginal := sum(6/49, 15/49)

After

Y column1 marginal = 3/7

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

joint cell row0 column0 marginal product := mul(2/7, 4/7)

After

joint cell row0 column0 marginal product = 8/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · implies

Before

original row=0;column=0;value labels=[2, -3];joint mass=8/49;marginal product=8/49

After

cell factorizes=Yes

Conditions: none

Audit every cell's singleton-event product,including zeros.One failed cell gives a singleton-preimage counterexample.Retain original row-major failure order.

Step identifiers and dependencies

Rule: RV_independence_every_joint_cell · Uses: G001, S008

S010 · calculation

Before

joint cell row0 column1 marginal product := mul(2/7, 3/7)

After

joint cell row0 column1 marginal product = 6/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

original row=0;column=1;value labels=[2, 34];joint mass=6/49;marginal product=6/49

After

cell factorizes=Yes

Conditions: none

Audit every cell's singleton-event product,including zeros.One failed cell gives a singleton-preimage counterexample.Retain original row-major failure order.

Step identifiers and dependencies

Rule: RV_independence_every_joint_cell · Uses: G001, S010

S012 · calculation

Before

joint cell row1 column0 marginal product := mul(5/7, 4/7)

After

joint cell row1 column0 marginal product = 20/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · implies

Before

original row=1;column=0;value labels=[27, -3];joint mass=20/49;marginal product=20/49

After

cell factorizes=Yes

Conditions: none

Audit every cell's singleton-event product,including zeros.One failed cell gives a singleton-preimage counterexample.Retain original row-major failure order.

Step identifiers and dependencies

Rule: RV_independence_every_joint_cell · Uses: G001, S012

S014 · calculation

Before

joint cell row1 column1 marginal product := mul(5/7, 3/7)

After

joint cell row1 column1 marginal product = 15/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · implies

Before

original row=1;column=1;value labels=[27, 34];joint mass=15/49;marginal product=15/49

After

cell factorizes=Yes

Conditions: none

Audit every cell's singleton-event product,including zeros.One failed cell gives a singleton-preimage counterexample.Retain original row-major failure order.

Step identifiers and dependencies

Rule: RV_independence_every_joint_cell · Uses: G001, S014

S016 · implies

Before

all joint factorization failures=[]

After

random variables independent=Yes;all-cell factorization covers every value-event rectangle

Conditions: none

If every cell factorizes,any value-event rectangle sum splits into a product of marginal sums,covering every preimage-event choice.This implies no identical distribution,IID,Markov behavior or larger-family mutual independence.

Step identifiers and dependencies

Rule: RV_all_cells_to_all_event_preimages · Uses: G001, S015

S017 · calculation

Before

moment row0 col0 weighted X := mul(8/49, 2)

After

moment row0 col0 weighted X = 16/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · calculation

Before

moment row0 col0 weighted Y := mul(8/49, -3)

After

moment row0 col0 weighted Y = -24/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S017

S019 · calculation

Before

moment row0 col0 XY := mul(2, -3)

After

moment row0 col0 XY = -6

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · calculation

Before

moment row0 col0 weighted XY := mul(8/49, -6)

After

moment row0 col0 weighted XY = -48/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S019

S021 · calculation

Before

moment row0 col1 weighted X := mul(6/49, 2)

After

moment row0 col1 weighted X = 12/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S020

S022 · calculation

Before

moment row0 col1 weighted Y := mul(6/49, 34)

After

moment row0 col1 weighted Y = 204/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S021

S023 · calculation

Before

moment row0 col1 XY := mul(2, 34)

After

moment row0 col1 XY = 68

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S022

S024 · calculation

Before

moment row0 col1 weighted XY := mul(6/49, 68)

After

moment row0 col1 weighted XY = 408/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S023

S025 · calculation

Before

moment row1 col0 weighted X := mul(20/49, 27)

After

moment row1 col0 weighted X = 540/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S024

S026 · calculation

Before

moment row1 col0 weighted Y := mul(20/49, -3)

After

moment row1 col0 weighted Y = -60/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S025

S027 · calculation

Before

moment row1 col0 XY := mul(27, -3)

After

moment row1 col0 XY = -81

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S026

S028 · calculation

Before

moment row1 col0 weighted XY := mul(20/49, -81)

After

moment row1 col0 weighted XY = -1620/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S027

S029 · calculation

Before

moment row1 col1 weighted X := mul(15/49, 27)

After

moment row1 col1 weighted X = 405/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S028

S030 · calculation

Before

moment row1 col1 weighted Y := mul(15/49, 34)

After

moment row1 col1 weighted Y = 510/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S029

S031 · calculation

Before

moment row1 col1 XY := mul(27, 34)

After

moment row1 col1 XY = 918

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S030

S032 · calculation

Before

moment row1 col1 weighted XY := mul(15/49, 918)

After

moment row1 col1 weighted XY = 13770/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S031

S033 · calculation

Before

grid E_X := sum(16/49, 12/49, 540/49, 405/49)

After

grid E_X = 139/7

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S032

S034 · calculation

Before

grid E_Y := sum(-24/49, 204/49, -60/49, 510/49)

After

grid E_Y = 90/7

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S033

S035 · calculation

Before

grid E_XY := sum(-48/49, 408/49, -1620/49, 13770/49)

After

grid E_XY = 12510/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S034

S036 · calculation

Before

grid product of means := mul(139/7, 90/7)

After

grid product of means = 12510/49

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S035

S037 · calculation

Before

grid covariance := sub(12510/49, 12510/49)

After

grid covariance = 0

Conditions: none

Compute exactly from original roles,complete pairings and established intermediates,retaining denominators,signs and zeros.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S036

S038 · implies

Before

verified independence=Yes;E_X=139/7;E_Y=90/7;E_XY=12510/49;covariance=0

After

source implication_pass is conjunction(independent,covariance0)=Yes,not material implication

Conditions: none

Verified all-cell independence distributes the finite double sum to E[XY]=E[X]E[Y],hence Cov=0.Despite the field name implication_pass,the protocol asks both facts to hold.A dependent zero-covariance model still returns No;this neither refutes the theorem nor proves the converse.

Step identifiers and dependencies

Rule: RV_zero_covariance_conjunction_not_converse · Uses: G001, S037

Reverse checks

  • S038 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S037 · premise_and_result_audit — Recompute grid covariance with exact rational arithmetic, not rounded decimals.
  • S036 · premise_and_result_audit — Recompute grid product of means with exact rational arithmetic, not rounded decimals.
  • S035 · premise_and_result_audit — Recompute grid E_XY with exact rational arithmetic, not rounded decimals.
  • S034 · premise_and_result_audit — Recompute grid E_Y with exact rational arithmetic, not rounded decimals.
  • S033 · premise_and_result_audit — Recompute grid E_X with exact rational arithmetic, not rounded decimals.
  • S032 · premise_and_result_audit — Recompute moment row1 col1 weighted XY with exact rational arithmetic, not rounded decimals.
  • S031 · premise_and_result_audit — Recompute moment row1 col1 XY with exact rational arithmetic, not rounded decimals.
  • S030 · premise_and_result_audit — Recompute moment row1 col1 weighted Y with exact rational arithmetic, not rounded decimals.
  • S029 · premise_and_result_audit — Recompute moment row1 col1 weighted X with exact rational arithmetic, not rounded decimals.
  • S028 · premise_and_result_audit — Recompute moment row1 col0 weighted XY with exact rational arithmetic, not rounded decimals.
  • S027 · premise_and_result_audit — Recompute moment row1 col0 XY with exact rational arithmetic, not rounded decimals.
  • S026 · premise_and_result_audit — Recompute moment row1 col0 weighted Y with exact rational arithmetic, not rounded decimals.
  • S025 · premise_and_result_audit — Recompute moment row1 col0 weighted X with exact rational arithmetic, not rounded decimals.
  • S024 · premise_and_result_audit — Recompute moment row0 col1 weighted XY with exact rational arithmetic, not rounded decimals.
  • S023 · premise_and_result_audit — Recompute moment row0 col1 XY with exact rational arithmetic, not rounded decimals.
  • S022 · premise_and_result_audit — Recompute moment row0 col1 weighted Y with exact rational arithmetic, not rounded decimals.
  • S021 · premise_and_result_audit — Recompute moment row0 col1 weighted X with exact rational arithmetic, not rounded decimals.
  • S020 · premise_and_result_audit — Recompute moment row0 col0 weighted XY with exact rational arithmetic, not rounded decimals.
  • S019 · premise_and_result_audit — Recompute moment row0 col0 XY with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Recompute moment row0 col0 weighted Y with exact rational arithmetic, not rounded decimals.
  • S017 · premise_and_result_audit — Recompute moment row0 col0 weighted X with exact rational arithmetic, not rounded decimals.
  • S016 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S015 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S014 · premise_and_result_audit — Recompute joint cell row1 column1 marginal product with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S012 · premise_and_result_audit — Recompute joint cell row1 column0 marginal product with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S010 · premise_and_result_audit — Recompute joint cell row0 column1 marginal product with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S008 · premise_and_result_audit — Recompute joint cell row0 column0 marginal product with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute Y column1 marginal with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Y column0 marginal with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute X row1 marginal with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute X row0 marginal with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S002 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S001 · premise_and_result_audit — Recompute joint grid model whole mass sum with exact rational arithmetic, not rounded decimals.

Result

(Yes, 139/7, 90/7, 12510/49, 0, Yes, zero_covariance_converse_not_claimed)

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.

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.

Source hashes and review receipts
  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: 90f14099d69ec5290531c3003f21cee0092d56121236340a489b881c792577aa
  • candidate record SHA-256: a3b3c7b6390524160049bf09e2550f1ff6d275df78948d5c62cefb5d6e396262
  • semantic review receipt SHA-256: e49bf5eaa968c09ebac4ad538ce58251671ed922c957cee1471cfc7b68934bfe
  • question-first witness SHA-256: a7976057c26051fab92342fc95d48af224466c0e1e4ab6ae4c8811c02772e6da
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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