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Question 19459: Proper Coloring Alone Does Not Prove the Chromatic Minimum

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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R0037-19459 · q-20261014-advance-20261106-r01-chromatic-number-0009

Original question and givens

Use the complete finite loop-free simple undirected graph on Fin(6)={0,…,5} with canonical edges=[[0, 1], [0, 5], [1, 2], [1, 4], [2, 3], [3, 4], [4, 5]]. All graph vertices and edges are supplied, and exact searches are limited to n≤9. Supplied colors=[0, 1, 0, 1, 0, 1] in vertex order. Color labels are nonnegative integer palette indices; retain their actual labels. Properness checks every edge, and using palette [0,k) is separate from merely using at most k distinct labels. Give (colors, used_colors, color_count, proper, boundary).

  • G001 — Use the complete finite loop-free simple undirected graph on Fin(6)={0,…,5} with canonical edges=[[0, 1], [0, 5], [1, 2], [1, 4], [2, 3], [3, 4], [4, 5]]. All graph vertices and edges are supplied, and exact searches are limited to n≤9. Supplied colors=[0, 1, 0, 1, 0, 1] in vertex order. Color labels are nonnegative integer palette indices; retain their actual labels. Properness checks every edge, and using palette [0,k) is separate from merely using at most k distinct labels. Give (colors, used_colors, color_count, proper, boundary).

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 operation=chromatic-proper-audit;original snapshot and mathematics retained

After

explicit ordered source output fields=[colors, used_colors, color_count, proper, boundary]

Conditions: none

Retain the historical interface marker in the original snapshot while listing ordered source fields here,without JavaScript or external lookup.Field names are not mathematical evidence,and No retains the operation's specific claim scope.

Step identifiers and dependencies

Rule: source_ordered_interface_explicit_without_javascript · Uses: G001

S002 · implies

Before

ACTUAL complete finite carrier Fin(6);ALL original canonical simple undirected edges=[[0, 1], [0, 5], [1, 2], [1, 4], [2, 3], [3, 4], [4, 5]]

After

use full original vertex/edge data;exact search domain n<=9;empty carrier and isolated vertices RETAINED

Conditions: none

Retain every original vertex and edge.This family includes n=0 rather than importing a previous nonempty-carrier guard or deleting isolates.Actual palette labels must not be replaced by semantic relabeling.

Step identifiers and dependencies

Rule: chromatic_complete_graph_not_semantic_color_relabeling · Uses: G001, S001

S003 · implies

Before

original edge index=0;actual endpoint vertices=[0, 1];ORIGINAL palette labels=[0, 1]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S002

S004 · implies

Before

original edge index=1;actual endpoint vertices=[0, 5];ORIGINAL palette labels=[0, 1]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S003

S005 · implies

Before

original edge index=2;actual endpoint vertices=[1, 2];ORIGINAL palette labels=[1, 0]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S004

S006 · implies

Before

original edge index=3;actual endpoint vertices=[1, 4];ORIGINAL palette labels=[1, 0]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S005

S007 · implies

Before

original edge index=4;actual endpoint vertices=[2, 3];ORIGINAL palette labels=[0, 1]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S006

S008 · implies

Before

original edge index=5;actual endpoint vertices=[3, 4];ORIGINAL palette labels=[1, 0]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S007

S009 · implies

Before

original edge index=6;actual endpoint vertices=[4, 5];ORIGINAL palette labels=[0, 1]

After

endpoint labels different=Yes

Conditions: none

Check different colors on every original edge.Numeric labels distinguish colors,not the number of colors.One failed supplied coloring does not establish nonexistence of another proper coloring.

Step identifiers and dependencies

Rule: chromatic_every_original_edge_properness · Uses: G001, S008

S010 · calculation

Before

chromatic distinct used label count := sum(1, 1)

After

chromatic distinct used label count = 2

Conditions: none

Substitute original roles and established intermediates exactly,retaining parameter,outcome,target and denominator roles without replacing the claim.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

ORIGINAL complete color array=[0, 1, 0, 1, 0, 1];ALL edge properness flags=[Yes, Yes, Yes, Yes, Yes, Yes, Yes]

After

increasingly ordered DISTINCT used labels=[0, 1];distinct count=2;proper=Yes;not max_label+1

Conditions: none

Count distinct labels rather than max_label+1,with0 for an empty array.A proper supplied coloring gives an upper bound,not minimum status from greediness or small labels.

Step identifiers and dependencies

Rule: chromatic_distinct_label_count_not_palette_range_or_minimum · Uses: G001, S010

Reverse checks

  • 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 chromatic distinct used label count with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S006 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S005 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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, 1, 0, 1, 0, 1], [0, 1], 2, Yes, proper_coloring_only)

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: 6e4431da49bb25c52ad4a96fbde7dffc1801b08e6db486cb5bb5f7cc228b42ed
  • candidate record SHA-256: 5af81cb9510d0c23646133b63d0dd725868224a290f89bbcd539ad406be579d7
  • semantic review receipt SHA-256: 065507b602ceee60cf47a700d387a51940e0c6724c35a3336a7a7948a199ed80
  • question-first witness SHA-256: 7203f33b030792559673b0fee520a8c0e70903c4dd970b35293aa40852f333d6
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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