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Question 4010: Candidate Sign and Squared-Distance Defect

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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R0007-04010 · q-20261008-advance-20261010-r03-distance-formula-0035

Original question and givens

In one equal-unit orthogonal Euclidean plane, L2 is the nonnegative distance from the common origin to each vector. Vector=[9, 10], integer candidate c=-12. Give (is c nonnegative?, c²−L2²). The first field tests only sign, not full distance eligibility.

  • G001 — In one equal-unit orthogonal Euclidean plane, L2 is the nonnegative distance from the common origin to each vector. Vector=[9, 10], integer candidate c=-12. Give (is c nonnegative?, c²−L2²). The first field tests only sign, not full distance eligibility.

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

integer vectors from a common origin;orthogonal equal-length units

After

L2(v)≥0 and L2(v)²=v₁²+v₂²

Conditions: none

A common origin,orthogonality and equal units support the sum-of-squares formula;coordinates may be negative but distances may not.

Step identifiers and dependencies

Rule: euclidean_distance_frame · Uses: G001

S002 · calculation

Before

candidate vector coordinate1 squared := square(9)

After

candidate vector coordinate1 squared = 81

Conditions: none

Square the entire coordinate,including a negative sign inside the square.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

candidate vector coordinate2 squared := square(10)

After

candidate vector coordinate2 squared = 100

Conditions: none

Square the entire coordinate,including a negative sign inside the square.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

candidate vector L2 squared := sum(81, 100)

After

candidate vector L2 squared = 181

Conditions: none

Add the coordinate squares to obtain squared distance,not a sum of the coordinates.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

candidate squared := square(-12)

After

candidate squared = 144

Conditions: none

Square the candidate before comparing with squared distance.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

signed square defect := sub(144, 181)

After

signed square defect = -37

Conditions: none

The signed defect is c²−L2²,not its absolute value.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · implies

Before

c=-12;c≥0=No;c²−L2²=-37

After

report sign and defect separately

Conditions: none

The first field asks only whether the candidate is nonnegative;full distance validity also requires defect0.A negative candidate is not a distance even if its square matches.

Step identifiers and dependencies

Rule: distance_sign_and_defect · Uses: G001, S006

Reverse checks

  • 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 signed square defect with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute candidate squared with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute candidate vector L2 squared with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute candidate vector coordinate2 squared with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute candidate vector coordinate1 squared 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

(No, -37)

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: beed7385f662e282854e995439ccaa7239eed25cd1957ea9c99f08ac6569cfaf
  • candidate record SHA-256: 6b64734ace136e1ff6f554fd9ee3d7d2f52cacc3a546a40547a46c9723a89379
  • semantic review receipt SHA-256: faf0582c0184613e6fae207374056133eae600883a29c67d8438113bbe3c485a
  • question-first witness SHA-256: 4b283b6ff424b1d22caa36f3552b0fa21b1b66a0a883d7cbe9cedc8dd77b2e42
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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