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Question 13473: Distinguish a Completeness Theorem from Sampled Cauchy Sequences

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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R0025-13473 · q-20261014-advance-20261028-r03-real-banach-space-0098

Original question and givens

Use the explicit real coordinate space R^n of dimension=23, with the named norm=l1, limited to l1 or linfinity. A Banach certificate must bind the carrier, vector operations, norm, the metric induced by that same norm, and completeness of that same space. The named finite-dimensional real normed-space theorem is a universal mathematical premise, not a new Lean receipt or sampled-sequence proof. No Hilbert, compactness or arbitrary infinite-dimensional conclusion is inferred. evidence_mode=finite_dimensional_theorem. Give (dimension,norm_name,evidence_mode,sufficient?,boundary). finite_dimensional_theorem yields universal_named_certificate; sampled_cauchy_sequences yields samples_insufficient_for_completeness.

  • G001 — Use the explicit real coordinate space R^n of dimension=23, with the named norm=l1, limited to l1 or linfinity. A Banach certificate must bind the carrier, vector operations, norm, the metric induced by that same norm, and completeness of that same space. The named finite-dimensional real normed-space theorem is a universal mathematical premise, not a new Lean receipt or sampled-sequence proof. No Hilbert, compactness or arbitrary infinite-dimensional conclusion is inferred. evidence_mode=finite_dimensional_theorem. Give (dimension,norm_name,evidence_mode,sufficient?,boundary). finite_dimensional_theorem yields universal_named_certificate; sampled_cauchy_sequences yields samples_insufficient_for_completeness.

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 real carrier R^23;standard coordinate vector operations;named norm=l1

After

metric is d(x,y)=this_same_norm(x-y);norm axioms supplied by named formula

Conditions: none

Carrier,vector operations,norm,induced metric and completeness must describe the same space.A completeness result for another metric cannot be transplanted.

Step identifiers and dependencies

Rule: Banach_same_space_norm_metric_binding · Uses: G001

S002 · implies

Before

arbitrary Cauchy sequence x_k in R^23 under l1;every coordinate obeys abs((x_k-x_m)_i)<=norm(x_k-x_m)

After

each real coordinate sequence is Cauchy;real-number completeness supplies a real limit L_i

Conditions: none

For every positive eta,the vector Cauchy tail bound controls every coordinate difference,so each coordinate is Cauchy.Real-number completeness is an explicit mathematical premise here,not a new Lean verification.

Step identifiers and dependencies

Rule: Banach_coordinate_Cauchy_and_real_completeness_premise · Uses: G001, S001

S003 · implies

Before

coordinate limits L_i form L in R^23;epsilon>0;each coordinate error eventually <epsilon/23

After

choose N=max of the 23 coordinate cutoffs;sum of 23 coordinate errors < 23*(epsilon/23)=epsilon;norm(x_k-L)->0

Conditions: none

Finite positive dimension permits one maximum cutoff for all coordinates.Use epsilon/n for l1 and the finite maximum for linfinity.This gives convergence in the same norm to L in the original space,not merely coordinatewise or ambient convergence.

Step identifiers and dependencies

Rule: Banach_finite_coordinate_limits_same_norm_convergence · Uses: G001, S002

S004 · implies

Before

every Cauchy sequence in this named real R^23 normed space has a same-space norm limit

After

Banach certificate=Yes;no Hilbert or arbitrary infinite-dimensional conclusion

Conditions: none

The universal argument closes completeness of this named finite-dimensional space.It does not infer an inner product,Hilbert structure,compactness or arbitrary infinite-dimensional conclusions.

Step identifiers and dependencies

Rule: named_finite_dimensional_Banach_certificate_scope · Uses: G001, S003

S005 · implies

Before

named real space R^23;norm=l1;evidence=finite_dimensional_theorem

After

sufficient evidence=Yes;sample insufficiency is not incompleteness

Conditions: none

The named universal theorem and coordinate argument cover every Cauchy sequence;finite samples do not.No in sample mode neither declares this known space incomplete nor supplies a formal-verification receipt.

Step identifiers and dependencies

Rule: Banach_evidence_quantifier_scope · 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

(23, l1, finite_dimensional_theorem, Yes, universal_named_certificate)

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: 8bb8596d0dbb1854958de3ad647efda30a974e98f03d34fd39d9787dfbe79ad5
  • candidate record SHA-256: 982cf55e5fb687048479e4a391b4bffe087b4690aa4c7761ba8b250c6650b86f
  • semantic review receipt SHA-256: 0e51c2bf621e6e998415fdd75d260464e625cecd5894a230c9f09553249551c5
  • question-first witness SHA-256: ceb79401a62782c9f7e5ed86afee9b1a71455f799bd24cf485cba7aa8ecaca8a
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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