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Question 34904: Exact Distance Between Rational Points

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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R0068-34904 · q-20260923-real-rational-point-distance-0004

Original question and givens

Two rational real points are -7/4 and 9/4. Find the exact distance |-7/4−9/4| as a lowest-terms fraction.

  • G001 — Two rational real points are -7/4 and 9/4. Find the exact distance |-7/4−9/4| as a lowest-terms fraction.

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-real-rational-point-distance, [left, operation, right]]

After

derived = [exact_rational_distance, no-invented-domain]

Conditions: none

Separate source banks:legacy RAW SAFE with unbounded derived BigInts versus BASE Number.isInteger without invented SAFE/million caps.Operations,domains and permissive/exact keys follow THIS bank.Keep ORIGINAL JSON intact.

Step identifiers and dependencies

Rule: R68_BANK_specific_keys_operations_and_numeric_guards · Uses: G001

S002 · calculation

Before

Real ORIGINAL left point ORIGINAL exact numerator over nonzero denominator := div(-7, 4)

After

Real ORIGINAL left point ORIGINAL exact numerator over nonzero denominator = -7/4

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · implies

Before

source roles = [Real ORIGINAL left point, [-7, 4]]

After

derived = [[-7, 4], -7/4]

Conditions: none

BASE normalizeFraction requires INTEGER components and nonzero denominator,without invented SAFE/million/100million caps.Normalize denominator sign and gcd;zero is0/1.This derived representation does not alter the ORIGINAL raw pair.

Step identifiers and dependencies

Rule: Real_BASE_fraction_sign_gcd_normalization_NO_invented_SAFEcap · Uses: G001, S002

S004 · calculation

Before

Real ORIGINAL right point ORIGINAL exact numerator over nonzero denominator := div(9, 4)

After

Real ORIGINAL right point ORIGINAL exact numerator over nonzero denominator = 9/4

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

source roles = [Real ORIGINAL right point, [9, 4]]

After

derived = [[9, 4], 9/4]

Conditions: none

BASE normalizeFraction requires INTEGER components and nonzero denominator,without invented SAFE/million/100million caps.Normalize denominator sign and gcd;zero is0/1.This derived representation does not alter the ORIGINAL raw pair.

Step identifiers and dependencies

Rule: Real_BASE_fraction_sign_gcd_normalization_NO_invented_SAFEcap · Uses: G001, S004

S006 · calculation

Before

Real ORIGINAL normalized left numerator times right positive denominator := mul(-7, 4)

After

Real ORIGINAL normalized left numerator times right positive denominator = -28

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

Real ORIGINAL normalized right numerator times left positive denominator := mul(9, 4)

After

Real ORIGINAL normalized right numerator times left positive denominator = 36

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

Real distance ORIGINAL signed crossproduct difference := sub(-28, 36)

After

Real distance ORIGINAL signed crossproduct difference = -64

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

Real distance ORIGINAL positive denominator product := mul(4, 4)

After

Real distance ORIGINAL positive denominator product = 16

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · implies

Before

source roles = [-7/4, 9/4, -64, 16]

After

derived = [64, 16]

Conditions: none

Real-line distance is|left−right|.Retain the signed difference BEFORE taking abs.Equal points have distance0;do not return signed or squared distance or guess a sign by reordering points.

Step identifiers and dependencies

Rule: Real_DISTANCE_absolute_difference_NOT_signed_or_squared · Uses: G001, S009

S011 · calculation

Before

Real exact distance derived fraction ORIGINAL exact numerator over nonzero denominator := div(64, 16)

After

Real exact distance derived fraction ORIGINAL exact numerator over nonzero denominator = 4

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · implies

Before

source roles = [Real exact distance derived fraction, [64, 16]]

After

derived = [[4, 1], 4/1]

Conditions: none

BASE normalizeFraction requires INTEGER components and nonzero denominator,without invented SAFE/million/100million caps.Normalize denominator sign and gcd;zero is0/1.This derived representation does not alter the ORIGINAL raw pair.

Step identifiers and dependencies

Rule: Real_BASE_fraction_sign_gcd_normalization_NO_invented_SAFEcap · Uses: G001, S011

Reverse checks

  • S012 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S011 · premise_and_result_audit — Recompute Real exact distance derived fraction ORIGINAL exact numerator over nonzero denominator with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S009 · premise_and_result_audit — Recompute Real distance ORIGINAL positive denominator product with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute Real distance ORIGINAL signed crossproduct difference with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute Real ORIGINAL normalized right numerator times left positive denominator with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Real ORIGINAL normalized left numerator times right positive denominator with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S004 · premise_and_result_audit — Recompute Real ORIGINAL right point ORIGINAL exact numerator over nonzero denominator with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S002 · premise_and_result_audit — Recompute Real ORIGINAL left point ORIGINAL exact numerator over nonzero denominator with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.

Result

4/1

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: 8f8124755b2c40360811bba8f24ebad9fa3ca75a90b29f64065bf41b88a1e517
  • candidate record SHA-256: 55e40de38455550a87ba7b77cad11668eacff098a2fa6c7946fd10ebce96cc87
  • semantic review receipt SHA-256: e7a54104fa02c235f7591329bd6db8d626dd74bf0fae29c557b1f269c85066ed
  • question-first witness SHA-256: 8401a3c2064c1275a6a7ea8f00412fa12286cec7b2db6c305ff9dba3724ae229
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON