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Question 8236: Scaled Rational Values and Order Direction

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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R0015-08236 · q-20261012-advance-20261017-r04-order-relation-0086

Original question and givens

Use the usual total order on R, restricted to exact rational inputs whose original denominators are positive. Output reduced fractions with positive denominators, retaining /1; do not extrapolate to arbitrary partial orders or complex numbers. a=-2/3, b=-1/2, t=3/3. Give (a, b, t, t*a, t*b, original comparison, scaled comparison, order-preserved/order-reversed/collapsed according to the sign of t).

  • G001 — Use the usual total order on R, restricted to exact rational inputs whose original denominators are positive. Output reduced fractions with positive denominators, retaining /1; do not extrapolate to arbitrary partial orders or complex numbers. a=-2/3, b=-1/2, t=3/3. Give (a, b, t, t*a, t*b, original comparison, scaled comparison, order-preserved/order-reversed/collapsed according to the sign of t).

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

usual total order on R;all original denominators positive

After

closed endpoints included;negative scaling reverses;zero collapses

Conditions: none

These exact rationals use the usual real total order,not complex numbers or an arbitrary partial order.Original denominators must be positive;normalizing a negative input denominator does not waive that contract.

Step identifiers and dependencies

Rule: real_rational_order_scope · Uses: G001

S002 · calculation

Before

scaled first value := mul(1, -2/3)

After

scaled first value = -2/3

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

scaled second value := mul(1, -1/2)

After

scaled second value = -1/2

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

original order left cross := mul(-2, 2)

After

original order left cross = -4

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

original order right cross := mul(-1, 3)

After

original order right cross = -3

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

original order cross residual := sub(-4, -3)

After

original order cross residual = -1

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · implies

Before

original order:fractions=[-2/3, -1/2]

After

cross residual=-1;comparison=<

Conditions: none

Reduced denominators are positive,so the cross-difference sign determines order.Retain equality and use original indices separately to break equal-value sorting ties.

Step identifiers and dependencies

Rule: rational_positive_denominator_comparison · Uses: G001, S006

S008 · calculation

Before

scaled order left cross := mul(-2, 2)

After

scaled order left cross = -4

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

scaled order right cross := mul(-1, 3)

After

scaled order right cross = -3

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

scaled order cross residual := sub(-4, -3)

After

scaled order cross residual = -1

Conditions: none

Substitute the source data exactly in the stated operand order;division requires a nonzero denominator.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

scaled order:fractions=[-2/3, -1/2]

After

cross residual=-1;comparison=<

Conditions: none

Reduced denominators are positive,so the cross-difference sign determines order.Retain equality and use original indices separately to break equal-value sorting ties.

Step identifiers and dependencies

Rule: rational_positive_denominator_comparison · Uses: G001, S010

S012 · implies

Before

scale=1/1;old comparison=<

After

new comparison=<;direction=order preserved

Conditions: none

The direction label depends on the scale's sign.Positive preserves,negative reverses,and zero collapses both values to0 even if originally equal.Equality remains equality under negative scaling.

Step identifiers and dependencies

Rule: order_scale_sign_three_cases · Uses: G001, S011

Reverse checks

  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S010 · premise_and_result_audit — Recompute scaled order cross residual with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute scaled order right cross with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute scaled order left cross with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S006 · premise_and_result_audit — Recompute original order cross residual with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute original order right cross with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute original order left cross with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute scaled second value with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute scaled first value with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.

Result

(-2/3, -1/2, 1/1, -2/3, -1/2, <, <, order-preserved)

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: 877fd5467b3a5663e778380fc5e64478c31855464e5010e886674b3908f0df2b
  • candidate record SHA-256: bb2a29bb2b92ef0f8e6f7c55f796edb32d307fef65886104c4b3b356b19e7a9b
  • semantic review receipt SHA-256: 6ecad9d909199221a07e923f87425e80b3bdec3eed46fe5910d04fca694cae18
  • question-first witness SHA-256: e8f00458977a09493b5f9f05ab9e6feec72debaf4c7d1c609d1fc95900a35a1b
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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