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Question 11061: An Exact Point from Qualified Convex Weights On this page Original question and givens Definition and scope Step-by-step derivation Reverse checks Result This question review and source binding Return to catalogue page 56
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This teaching derivation has second-context AI mathematical and bilingual semantic review, limited to the model and assumptions stated in this question. It has no human review or new Lean proof and does not promote the original question or MKO to Canonical truth.
R0021-11061 · q-20261013-advance-20261024-r05-finite-convex-combination-0036
Original question and givens Use a finite nonempty ordered vector list and aligned exact rational weights. Convex weights may be zero but must be nonnegative and sum exactly to 1, not merely approximately. A convex-combination witness establishes its weighted point, not unique coordinates without separate affine independence. vectors=[[-2, 0], [0, 2]], weights=[11/13, 2/13]. Require qualified weights. Give (original vectors,normalized aligned weights,weighted point). Use exact rational arithmetic, reduce fractions to positive denominators and omit /1 for integer outputs.
G001 — Use a finite nonempty ordered vector list and aligned exact rational weights. Convex weights may be zero but must be nonnegative and sum exactly to 1, not merely approximately. A convex-combination witness establishes its weighted point, not unique coordinates without separate affine independence. vectors=[[-2, 0], [0, 2]], weights=[11/13, 2/13]. Require qualified weights. Give (original vectors,normalized aligned weights,weighted point). Use exact rational arithmetic, reduce fractions to positive denominators and omit /1 for integer outputs.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
convex weights:raw rational pairs=[[11, 13], [2, 13]] After
convex weights:normalized=[11/13, 2/13] Conditions: none
Every original denominator must be nonzero.Reduce fractions to positive denominators without decimal approximation.
Step identifiers and dependencies Rule: exact_weight_normalization · Uses: G001
S002 · calculation Before
convex weights total := sum(11/13, 2/13) After
convex weights total = 1 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S001
S003 · implies Before
convex weights:weights=[11/13, 2/13];sum=1 After
nonnegative=Yes;total_one=Yes;qualified=Yes Conditions: none
Check nonnegativity and exact total one separately.Zero weights are allowed;negative weights or near-one totals are not repaired.
Step identifiers and dependencies Rule: separate_weight_guards · Uses: G001, S002
S004 · implies Before
convex point:ordered vectors=[[-2, 0], [0, 2]];aligned weights=[11/13, 2/13] After
dimension=2;preserve duplicates and order Conditions: none
Preserve vector order,duplicates and coefficient pairing.Sum every vector's contribution within the same coordinate.
Step identifiers and dependencies Rule: ordered_vector_weight_pairing · Uses: G001, S003
S005 · calculation Before
convex point coordinate0 term0 := mul(11/13, -2) After
convex point coordinate0 term0 = -22/13 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S004
S006 · calculation Before
convex point coordinate0 term1 := mul(2/13, 0) After
convex point coordinate0 term1 = 0 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S005
S007 · calculation Before
convex point coordinate0 sum := sum(-22/13, 0) After
convex point coordinate0 sum = -22/13 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S006
S008 · calculation Before
convex point coordinate1 term0 := mul(11/13, 0) After
convex point coordinate1 term0 = 0 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S007
S009 · calculation Before
convex point coordinate1 term1 := mul(2/13, 2) After
convex point coordinate1 term1 = 4/13 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S008
S010 · calculation Before
convex point coordinate1 sum := sum(0, 4/13) After
convex point coordinate1 sum = 4/13 Conditions: none
Compute exactly with this step's specified roles,retaining signs,denominators and original pairings.
Step identifiers and dependencies Rule: exact_rational_arithmetic · Uses: G001, S009
Reverse checks S010 · premise_and_result_audit — Recompute convex point coordinate1 sum with exact rational arithmetic, not rounded decimals.S009 · premise_and_result_audit — Recompute convex point coordinate1 term1 with exact rational arithmetic, not rounded decimals.S008 · premise_and_result_audit — Recompute convex point coordinate1 term0 with exact rational arithmetic, not rounded decimals.S007 · premise_and_result_audit — Recompute convex point coordinate0 sum with exact rational arithmetic, not rounded decimals.S006 · premise_and_result_audit — Recompute convex point coordinate0 term1 with exact rational arithmetic, not rounded decimals.S005 · premise_and_result_audit — Recompute convex point coordinate0 term0 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.S002 · premise_and_result_audit — Recompute convex weights total 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, 0], [0, 2]], [11/13, 2/13], [-22/13, 4/13]) 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: 0f7be61e2c22317a4075561dc822c87d881a50dboriginal question SHA-256: 1bf2c3257060ede990eb91aeb1e10a3f39c7bcf4bf2761383a5cdb0ecc50d8e1candidate record SHA-256: b0f72e0deb0c8f3cba877034bf6a8e75fee729be4b7477dc618420408f39168fsemantic review receipt SHA-256: 47d23d3735987d68e27733b051bdfa80a3616d44fb223b82bf2e6c8e46d49258question-first witness SHA-256: a857db558000724020d2d5e815cb6bc3e2c9e2933df295bf33eb478d3c695139Lean: NOT_RUN · human review: NOT_PERFORMEDSame-source full JSON