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Question 12518: Aggregate Both Marginals from the Same Qualified Joint Law

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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R0024-12518 · q-20261013-advance-20261026-r04-finite-joint-distribution-0043

Original question and givens

Use the complete list of distinct integer pairs=[[5, -1], [6, 0], [7, 1], [8, 4]] and their aligned exact masses=[1/8, 1/4, 1/8, 1/2] on one common finite probability space. Qualification requires every mass to be nonnegative and their exact sum to be 1; zero masses are allowed. Preserve pair-mass alignment. Marginals alone do not specify this joint law or imply independence. No continuous or infinite-support conclusion is claimed. Use exact reduced rational outputs with positive denominators; omit /1 for integers. The joint table must qualify first. Give (x_marginal,y_marginal), each as [label,mass] rows sorted numerically by label, retaining listed labels even when their aggregated mass is zero.

  • G001 — Use the complete list of distinct integer pairs=[[5, -1], [6, 0], [7, 1], [8, 4]] and their aligned exact masses=[1/8, 1/4, 1/8, 1/2] on one common finite probability space. Qualification requires every mass to be nonnegative and their exact sum to be 1; zero masses are allowed. Preserve pair-mass alignment. Marginals alone do not specify this joint law or imply independence. No continuous or infinite-support conclusion is claimed. Use exact reduced rational outputs with positive denominators; omit /1 for integers. The joint table must qualify first. Give (x_marginal,y_marginal), each as [label,mass] rows sorted numerically by label, retaining listed labels even when their aggregated mass is zero.

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 law exact total := sum(1/8, 1/4, 1/8, 1/2)

After

joint law exact total = 1

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001

S002 · implies

Before

original ordered support=[[5, -1], [6, 0], [7, 1], [8, 4]];raw aligned masses=[[1, 8], [1, 4], [1, 8], [1, 2]]

After

normalized aligned masses=[1/8, 1/4, 1/8, 1/2];nonnegative=Yes;total=1;qualified=Yes

Conditions: none

Keep the complete joint table's original pair-mass alignment with distinct support pairs.Zero masses are allowed.Check nonnegativity and exact unit total separately;do not substitute marginals or a uniform law.

Step identifiers and dependencies

Rule: whole_joint_table_not_marginal_substitution · Uses: G001, S001

S003 · calculation

Before

marginal coordinate0 label5 := sum(1/8)

After

marginal coordinate0 label5 = 1/8

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · implies

Before

coordinate=0;label=5;original support indices=[0]

After

aggregated marginal mass=1/8;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S003

S005 · calculation

Before

marginal coordinate0 label6 := sum(1/4)

After

marginal coordinate0 label6 = 1/4

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · implies

Before

coordinate=0;label=6;original support indices=[1]

After

aggregated marginal mass=1/4;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S005

S007 · calculation

Before

marginal coordinate0 label7 := sum(1/8)

After

marginal coordinate0 label7 = 1/8

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · implies

Before

coordinate=0;label=7;original support indices=[2]

After

aggregated marginal mass=1/8;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S007

S009 · calculation

Before

marginal coordinate0 label8 := sum(1/2)

After

marginal coordinate0 label8 = 1/2

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · implies

Before

coordinate=0;label=8;original support indices=[3]

After

aggregated marginal mass=1/2;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S009

S011 · calculation

Before

marginal coordinate1 label-1 := sum(1/8)

After

marginal coordinate1 label-1 = 1/8

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · implies

Before

coordinate=1;label=-1;original support indices=[0]

After

aggregated marginal mass=1/8;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S011

S013 · calculation

Before

marginal coordinate1 label0 := sum(1/4)

After

marginal coordinate1 label0 = 1/4

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · implies

Before

coordinate=1;label=0;original support indices=[1]

After

aggregated marginal mass=1/4;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S013

S015 · calculation

Before

marginal coordinate1 label1 := sum(1/8)

After

marginal coordinate1 label1 = 1/8

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · implies

Before

coordinate=1;label=1;original support indices=[2]

After

aggregated marginal mass=1/8;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S015

S017 · calculation

Before

marginal coordinate1 label4 := sum(1/2)

After

marginal coordinate1 label4 = 1/2

Conditions: none

Compute exactly from the original roles and complete established operands,without changing pairings,order or replacing guards by approximation.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · implies

Before

coordinate=1;label=4;original support indices=[3]

After

aggregated marginal mass=1/2;listed label retained even at mass0

Conditions: none

Aggregate equal-coordinate original atoms,then sort labels numerically.Retain every listed label even at zero aggregated mass;do not multiply marginals to invent a joint law.

Step identifiers and dependencies

Rule: joint_marginal_all_original_atoms · Uses: G001, S017

Reverse checks

  • S018 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S017 · premise_and_result_audit — Recompute marginal coordinate1 label4 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 — Recompute marginal coordinate1 label1 with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S013 · premise_and_result_audit — Recompute marginal coordinate1 label0 with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S011 · premise_and_result_audit — Recompute marginal coordinate1 label-1 with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S009 · premise_and_result_audit — Recompute marginal coordinate0 label8 with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S007 · premise_and_result_audit — Recompute marginal coordinate0 label7 with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S005 · premise_and_result_audit — Recompute marginal coordinate0 label6 with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S003 · premise_and_result_audit — Recompute marginal coordinate0 label5 with exact rational arithmetic, not rounded decimals.
  • 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 law exact total with exact rational arithmetic, not rounded decimals.

Result

([[5, 1/8], [6, 1/4], [7, 1/8], [8, 1/2]], [[-1, 1/8], [0, 1/4], [1, 1/8], [4, 1/2]])

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: 517e4fa6e9366790f3992462370dbe73c4a52d7c21b508192b6cb712f5124d58
  • candidate record SHA-256: e6c3034776d306b1550e583a9ecbe57f94729ae76f5f338476c7d4e3a6ec4b36
  • semantic review receipt SHA-256: 1c8f6c2c6c75852cb93c08235684ce9f32ebe86065c58c693a04257e772c2d35
  • question-first witness SHA-256: 05fd764b5f9f7fff6185003efe576d87632f6daf40606ac3839a7feafe4f80d8
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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