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Question 7563: Basis-Image Columns and Two Matrix-Vector Routes

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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← Question derivation index · Original question batch

R0014-07563 · q-20261012-advance-20261016-r03-linear-transformation-0013

Original question and givens

Use the explicitly declared matrix model on all R²→R² with column vectors. Finite test values do not prove an arbitrary function linear; the zero matrix defines a linear map. M=[[0, 1], [2, -1]], v=[1, -1]. Give (first column M*e1, second column M*e2, Mv, v1*column1+v2*column2).

  • G001 — Use the explicitly declared matrix model on all R²→R² with column vectors. Finite test values do not prove an arbitrary function linear; the zero matrix defines a linear map. M=[[0, 1], [2, -1]], v=[1, -1]. Give (first column M*e1, second column M*e2, Mv, v1*column1+v2*column2).

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

M=[[0, 1], [2, -1]];v=[1, -1]

After

declared R2 matrix model;finite values are not a test of an arbitrary function

Conditions: none

The declared matrix model Mv gives a linear map on all R² by distributivity.The listed finite evaluations do not prove an arbitrary function linear.The zero map is linear;nonzero values or invertibility are not required.

Step identifiers and dependencies

Rule: declared_linear_model_scope · Uses: G001

S002 · calculation

Before

Mv[0] term0 := mul(0, 1)

After

Mv[0] term0 = 0

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

Mv[0] term1 := mul(1, -1)

After

Mv[0] term1 = -1

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

Mv[0] row sum := sum(0, -1)

After

Mv[0] row sum = -1

Conditions: none

Add the already aligned component or position,without mixing coordinates.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

Mv[1] term0 := mul(2, 1)

After

Mv[1] term0 = 2

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Mv[1] term1 := mul(-1, -1)

After

Mv[1] term1 = 1

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

Mv[1] row sum := sum(2, 1)

After

Mv[1] row sum = 3

Conditions: none

Add the already aligned component or position,without mixing coordinates.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · implies

Before

M=[[0, 1], [2, -1]];e1=[1, 0];e2=[0, 1]

After

M e1=[0, 2];M e2=[1, -1]

Conditions: none

The first standard basis vector selects the first column,and the second selects the second column.Do not substitute rows for basis images.

Step identifiers and dependencies

Rule: basis_images_are_columns · Uses: G001, S007

S009 · calculation

Before

v0 column1[0] := mul(1, 0)

After

v0 column1[0] = 0

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

v0 column1[1] := mul(1, 2)

After

v0 column1[1] = 2

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

v1 column2[0] := mul(-1, 1)

After

v1 column2[0] = -1

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · calculation

Before

v1 column2[1] := mul(-1, -1)

After

v1 column2[1] = 1

Conditions: none

Multiply the specified scalar and component at this position;do not substitute an inner product or entrywise matrix product.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

basis reconstruction[0] := sum(0, -1)

After

basis reconstruction[0] = -1

Conditions: none

Add the already aligned component or position,without mixing coordinates.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · calculation

Before

basis reconstruction[1] := sum(2, 1)

After

basis reconstruction[1] = 3

Conditions: none

Add the already aligned component or position,without mixing coordinates.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · implies

Before

v=[1, -1];Mv=[-1, 3]

After

column reconstruction=[-1, 3]

Conditions: none

First compute Mv by row times column vector,then reconstruct it from the basis images.The two routes do not reuse a proposed answer.

Step identifiers and dependencies

Rule: basis_reconstruction_audit · Uses: G001, S014

Reverse checks

  • S015 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S014 · premise_and_result_audit — Recompute basis reconstruction[1] with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute basis reconstruction[0] with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute v1 column2[1] with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute v1 column2[0] with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute v0 column1[1] with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute v0 column1[0] with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S007 · premise_and_result_audit — Recompute Mv[1] row sum with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Mv[1] term1 with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Mv[1] term0 with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Mv[0] row sum with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute Mv[0] term1 with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute Mv[0] term0 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

([0, 2], [1, -1], [-1, 3], [-1, 3])

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: 815c2aab8d70da98b896bb75264e69e03b0630ceb8b42f1724a014776a07ad17
  • candidate record SHA-256: 34678e000040b0510c5cb80f6db2d0e3f83cccfa42ca433fe6aa19dfebf4e4a4
  • semantic review receipt SHA-256: 23ba8196e85a09c03add0a87f96bec5d67a00dc648d1d68eef89101525b41a77
  • question-first witness SHA-256: 17d59afc327b7cb8b6e588686d6dc1abbccd384d8ba32b8c046652f96821d705
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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