Explore related knowledge and questions →

Question 33761: Zero Total Mean Is Not Enough: Check Each Information Block

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

Return to catalogue page 169

← Question derivation index · Original question batch

R0066-33761 · q-20261014-advance-20261031-r07-martingale-0036

Original question and givens

Use four equiprobable outcomes with aligned increments=[11, -11, 12, -12] and current information block labels=[0, 0, 1, 1]. Give (conditional_rows,all_zero?,classification), with rows [block_label,increments_in_outcome_order,exact_block_mean] sorted by block label. Classification is conditional_mean_zero_difference or difference_fails_martingale_condition.

  • G001 — Use four equiprobable outcomes with aligned increments=[11, -11, 12, -12] and current information block labels=[0, 0, 1, 1]. Give (conditional_rows,all_zero?,classification), with rows [block_label,increments_in_outcome_order,exact_block_mean] sorted by block label. Classification is conditional_mean_zero_difference or difference_fails_martingale_condition.

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 · implies

Before

source roles = [qf-mod31-martdeep-difference-mean, [blocks, domain, increments, operation]]

After

derived = [martdeep-difference-mean, Exact_finite_martingale_construction]

Conditions: none

THIS source uses LOCAL-hyphen operations with exact keys/domain.Keep source field order and numeric/Boolean/string roles;integer rational texts omit/1.Original questions,English,MKOs,ASTs and statuses remain unchanged.

Step identifiers and dependencies

Rule: R66_EXACT_source_bank_keys_local_operation_domain · Uses: G001

S002 · calculation

Before

Difference ORIGINAL block0 sum := sum(11, -11)

After

Difference ORIGINAL block0 sum = 0

Conditions: none

Calculate exactly from THIS step’s ORIGINAL ordered operands.Retain the SOURCE rational pre-reduction envelope separately;do not use floating values or silently widen a different bank.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · implies

Before

source roles = [Difference block0 mean, 1000000, 0, 2]

After

derived = [[0, 1], 0]

Conditions: none

Bound the SOURCE PRE-reduction numerator/denominator and require a nonzero denominator BEFORE sign/gcd normalization.MOD50 uses100million with NAIVE operations,not prior cross-cancellation;this Wave4 mean uses one million.Out-of-envelope is a source-slice hold,not mathematical falsity.

Step identifiers and dependencies

Rule: R66_SOURCE_PREreduction_components_then_sign_gcd · Uses: G001, S002

S004 · calculation

Before

Difference block0 mean ORIGINAL numerator over denominator := div(0, 2)

After

Difference block0 mean ORIGINAL numerator over denominator = 0

Conditions: none

Calculate exactly from THIS step’s ORIGINAL ordered operands.Retain the SOURCE rational pre-reduction envelope separately;do not use floating values or silently widen a different bank.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

source roles = [0, [0, 1], [11, -11]]

After

derived = [0]

Conditions: none

Conditioning four equiprobable outcomes on THIS information block leaves equal weights,so its conditional mean is the ORIGINAL increment sum divided by this block’s size.Check EVERY nonempty block,not global cancellation.

Step identifiers and dependencies

Rule: Martingale_EVERY_information_block_conditional_mean · Uses: G001, S004

S006 · calculation

Before

Difference ORIGINAL block1 sum := sum(12, -12)

After

Difference ORIGINAL block1 sum = 0

Conditions: none

Calculate exactly from THIS step’s ORIGINAL ordered operands.Retain the SOURCE rational pre-reduction envelope separately;do not use floating values or silently widen a different bank.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · implies

Before

source roles = [Difference block1 mean, 1000000, 0, 2]

After

derived = [[0, 1], 0]

Conditions: none

Bound the SOURCE PRE-reduction numerator/denominator and require a nonzero denominator BEFORE sign/gcd normalization.MOD50 uses100million with NAIVE operations,not prior cross-cancellation;this Wave4 mean uses one million.Out-of-envelope is a source-slice hold,not mathematical falsity.

Step identifiers and dependencies

Rule: R66_SOURCE_PREreduction_components_then_sign_gcd · Uses: G001, S006

S008 · calculation

Before

Difference block1 mean ORIGINAL numerator over denominator := div(0, 2)

After

Difference block1 mean ORIGINAL numerator over denominator = 0

Conditions: none

Calculate exactly from THIS step’s ORIGINAL ordered operands.Retain the SOURCE rational pre-reduction envelope separately;do not use floating values or silently widen a different bank.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · implies

Before

source roles = [1, [2, 3], [12, -12]]

After

derived = [0]

Conditions: none

Conditioning four equiprobable outcomes on THIS information block leaves equal weights,so its conditional mean is the ORIGINAL increment sum divided by this block’s size.Check EVERY nonempty block,not global cancellation.

Step identifiers and dependencies

Rule: Martingale_EVERY_information_block_conditional_mean · Uses: G001, S008

S010 · implies

Before

source roles = [[11, -11, 12, -12], [0, 0, 1, 1], [[0, [11, -11], 0], [1, [12, -12], 0]]]

After

derived = [Yes]

Conditions: none

Pass the conditional-difference obligation ONLY if EVERY information-block mean is0.A globally zero mean with a nonzero block still fails.

Step identifiers and dependencies

Rule: Martingale_DIFFERENCE_all_block_means_zero_required · Uses: G001, S009

Reverse checks

  • S010 · premise_and_result_audit — Reverse-audit THIS step against its ORIGINAL ordered roles and complete premises.Accept the conclusion only under these conditions;do not invert a one-way implication or call a finite check a general formal proof.
  • S009 · premise_and_result_audit — Reverse-audit THIS step against its ORIGINAL ordered roles and complete premises.Accept the conclusion only under these conditions;do not invert a one-way implication or call a finite check a general formal proof.
  • S008 · premise_and_result_audit — Recompute Difference block1 mean ORIGINAL numerator over denominator with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Reverse-audit THIS step against its ORIGINAL ordered roles and complete premises.Accept the conclusion only under these conditions;do not invert a one-way implication or call a finite check a general formal proof.
  • S006 · premise_and_result_audit — Recompute Difference ORIGINAL block1 sum with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Reverse-audit THIS step against its ORIGINAL ordered roles and complete premises.Accept the conclusion only under these conditions;do not invert a one-way implication or call a finite check a general formal proof.
  • S004 · premise_and_result_audit — Recompute Difference block0 mean ORIGINAL numerator over denominator with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Reverse-audit THIS step against its ORIGINAL ordered roles and complete premises.Accept the conclusion only under these conditions;do not invert a one-way implication or call a finite check a general formal proof.
  • S002 · premise_and_result_audit — Recompute Difference ORIGINAL block0 sum with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Reverse-audit THIS step against its ORIGINAL ordered roles and complete premises.Accept the conclusion only under these conditions;do not invert a one-way implication or call a finite check a general formal proof.

Result

([[0, [11, -11], 0], [1, [12, -12], 0]], Yes, conditional_mean_zero_difference)

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: b6382d01b23147f4b0d5c2324ae3f134566a3381549e97838df367cd051f1e46
  • candidate record SHA-256: 7782cb11559bb1cb643362ad6bb2354dc2bf9c369d2f387a476cfe64fa67754c
  • semantic review receipt SHA-256: 99b4f114b2ec93164b6aa5681e0107033a240e7a3f0a8988633ba65320ede267
  • question-first witness SHA-256: d9bd3a1940da8a73f790ee3fe460c9a8523791bdbe72c8e0304e3740b66710cc
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON