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Question 16804: An Invalid Supplied Cover Does Not Refute Finite-Space Compactness

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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R0032-16804 · q-20261014-advance-20261102-r05-compact-topological-space-0029

Original question and givens

Use the complete finite topology=[[], [0], [0, 1], [0, 1, 3], [0, 1, 3, 4], [0, 1, 2, 3, 4]] on the same carrier Fin(5)={0,…,4}. Each subset is an increasing duplicate-free carrier list. Validate the unique empty/whole opens and all finite union/intersection closure obligations first. All complements, closed sets, closures, interiors and boundaries refer to this same carrier/topology; no metric or visual boundary is silently supplied. Target=[0, 1, 3, 4], original ordered cover=[[0, 1], [0, 1, 3, 4], [0, 1, 2, 3, 4]]. Every original member must be open and the original union must contain the target. A subcover selects only original family indexes, starting at 0, sorted increasingly with duplicate indexes forbidden. This supplied-cover audit is separate from the universal finite-space compactness theorem. Give (invalid_open_indexes,covered_union,covers_target?,valid_cover?).

  • G001 — Use the complete finite topology=[[], [0], [0, 1], [0, 1, 3], [0, 1, 3, 4], [0, 1, 2, 3, 4]] on the same carrier Fin(5)={0,…,4}. Each subset is an increasing duplicate-free carrier list. Validate the unique empty/whole opens and all finite union/intersection closure obligations first. All complements, closed sets, closures, interiors and boundaries refer to this same carrier/topology; no metric or visual boundary is silently supplied. Target=[0, 1, 3, 4], original ordered cover=[[0, 1], [0, 1, 3, 4], [0, 1, 2, 3, 4]]. Every original member must be open and the original union must contain the target. A subcover selects only original family indexes, starting at 0, sorted increasingly with duplicate indexes forbidden. This supplied-cover audit is separate from the universal finite-space compactness theorem. Give (invalid_open_indexes,covered_union,covers_target?,valid_cover?).

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

same complete carrier Fin(5);original ordered complete topology=[[], [0], [0, 1], [0, 1, 3], [0, 1, 3, 4], [0, 1, 2, 3, 4]]

After

unique empty/whole opens=Yes;ordered open pairs checked=36;first union failure=null;first intersection failure=null

Conditions: none

Each subset is increasing and duplicate-free.The topology has unique empty/whole opens and closure under every binary union/intersection.Finitely many distinct opens reduce arbitrary unions to finite ones,handled by binary closure and the empty set.No metric is supplied.Keep original topology order.

Step identifiers and dependencies

Rule: topology_complete_finite_parent_all_pairs · Uses: G001

S002 · implies

Before

original supplied cover index=0;member=[0, 1];same full topology=[[], [0], [0, 1], [0, 1, 3], [0, 1, 3, 4], [0, 1, 2, 3, 4]]

After

original member open=Yes

Conditions: none

Audit every original member's openness,retaining equal sets at distinct indices.An unselected nonopen original member is not erased.This qualifies the supplied family,not the space's compactness.

Step identifiers and dependencies

Rule: compact_every_original_supplied_member_open · Uses: G001, S001

S003 · implies

Before

original supplied cover index=1;member=[0, 1, 3, 4];same full topology=[[], [0], [0, 1], [0, 1, 3], [0, 1, 3, 4], [0, 1, 2, 3, 4]]

After

original member open=Yes

Conditions: none

Audit every original member's openness,retaining equal sets at distinct indices.An unselected nonopen original member is not erased.This qualifies the supplied family,not the space's compactness.

Step identifiers and dependencies

Rule: compact_every_original_supplied_member_open · Uses: G001, S002

S004 · implies

Before

original supplied cover index=2;member=[0, 1, 2, 3, 4];same full topology=[[], [0], [0, 1], [0, 1, 3], [0, 1, 3, 4], [0, 1, 2, 3, 4]]

After

original member open=Yes

Conditions: none

Audit every original member's openness,retaining equal sets at distinct indices.An unselected nonopen original member is not erased.This qualifies the supplied family,not the space's compactness.

Step identifiers and dependencies

Rule: compact_every_original_supplied_member_open · Uses: G001, S003

S005 · implies

Before

same supplied target=[0, 1, 3, 4];whole original family union=[0, 1, 2, 3, 4];nonopen indices=[]

After

covers target=Yes;original supplied cover valid=Yes

Conditions: none

Coverage means containment of the supplied target;the union may be larger.Both all-member openness and coverage are required.A failed supplied family does not refute the finite-space universal theorem.

Step identifiers and dependencies

Rule: compact_supplied_openness_and_coverage_not_universal_theorem · Uses: G001, S004

Reverse checks

  • 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, 2, 3, 4], Yes, Yes)

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: acb91691cc1092321812d3c051859fb49017bdd90794af532ff9bf67e999107e
  • candidate record SHA-256: 9485bfb1c6c3dac439cd4a360968d03295691ad426bfb70394898028ec34b8b6
  • semantic review receipt SHA-256: d64b4e08bda1c25dd393b7c7e4140a8734610a9b84ae47e6f0adcff7f30a0b8e
  • question-first witness SHA-256: 790fd6623c04ba52a6ffb0a95cea52b532a02b23bb9453926d2d9f7a825fdec8
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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