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Question 20471: A Finite Increasing List Is Not an Already-Supplied Infinite Certificate

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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R0039-20471 · q-20261014-advance-20261107-r07-subsequence-0096

Original question and givens

Supplied finite natural-index list=[20, 21, 22, 23, 24, 25]. Give (indices, finite_prefix_increasing, infinite_certificate_supplied, boundary).

  • G001 — Supplied finite natural-index list=[20, 21, 22, 23, 24, 25]. Give (indices, finite_prefix_increasing, infinite_certificate_supplied, 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=subseq-finite-prefix-boundary;original snapshot and mathematics retained

After

explicit ordered source output fields=[indices, finite_prefix_increasing, infinite_certificate_supplied, boundary]

Conditions: none

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

Step identifiers and dependencies

Rule: source_ordered_interface_explicit_without_javascript · Uses: G001

S002 · calculation

Before

subsequence finite prefix adjacent index1 difference := sub(21, 20)

After

subsequence finite prefix adjacent index1 difference = 1

Conditions: none

Substitute original roles and established intermediates exactly,retaining indices,signs,denominators and the proof's applicability conditions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · implies

Before

ORIGINAL finite adjacent positions=[0, 1];actual indices=[20, 21]

After

exact forward difference=1;strictly increasing here=Yes

Conditions: none

Check every adjacent pair in original order without sorting or deduplicating to repair the prefix.Positive differences at all finite adjacent positions certify this prefix's strict increase.

Step identifiers and dependencies

Rule: subseq_finite_order_each_actual_adjacent_pair · Uses: G001, S002

S004 · calculation

Before

subsequence finite prefix adjacent index2 difference := sub(22, 21)

After

subsequence finite prefix adjacent index2 difference = 1

Conditions: none

Substitute original roles and established intermediates exactly,retaining indices,signs,denominators and the proof's applicability conditions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

ORIGINAL finite adjacent positions=[1, 2];actual indices=[21, 22]

After

exact forward difference=1;strictly increasing here=Yes

Conditions: none

Check every adjacent pair in original order without sorting or deduplicating to repair the prefix.Positive differences at all finite adjacent positions certify this prefix's strict increase.

Step identifiers and dependencies

Rule: subseq_finite_order_each_actual_adjacent_pair · Uses: G001, S004

S006 · calculation

Before

subsequence finite prefix adjacent index3 difference := sub(23, 22)

After

subsequence finite prefix adjacent index3 difference = 1

Conditions: none

Substitute original roles and established intermediates exactly,retaining indices,signs,denominators and the proof's applicability conditions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · implies

Before

ORIGINAL finite adjacent positions=[2, 3];actual indices=[22, 23]

After

exact forward difference=1;strictly increasing here=Yes

Conditions: none

Check every adjacent pair in original order without sorting or deduplicating to repair the prefix.Positive differences at all finite adjacent positions certify this prefix's strict increase.

Step identifiers and dependencies

Rule: subseq_finite_order_each_actual_adjacent_pair · Uses: G001, S006

S008 · calculation

Before

subsequence finite prefix adjacent index4 difference := sub(24, 23)

After

subsequence finite prefix adjacent index4 difference = 1

Conditions: none

Substitute original roles and established intermediates exactly,retaining indices,signs,denominators and the proof's applicability conditions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · implies

Before

ORIGINAL finite adjacent positions=[3, 4];actual indices=[23, 24]

After

exact forward difference=1;strictly increasing here=Yes

Conditions: none

Check every adjacent pair in original order without sorting or deduplicating to repair the prefix.Positive differences at all finite adjacent positions certify this prefix's strict increase.

Step identifiers and dependencies

Rule: subseq_finite_order_each_actual_adjacent_pair · Uses: G001, S008

S010 · calculation

Before

subsequence finite prefix adjacent index5 difference := sub(25, 24)

After

subsequence finite prefix adjacent index5 difference = 1

Conditions: none

Substitute original roles and established intermediates exactly,retaining indices,signs,denominators and the proof's applicability conditions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

ORIGINAL finite adjacent positions=[4, 5];actual indices=[24, 25]

After

exact forward difference=1;strictly increasing here=Yes

Conditions: none

Check every adjacent pair in original order without sorting or deduplicating to repair the prefix.Positive differences at all finite adjacent positions certify this prefix's strict increase.

Step identifiers and dependencies

Rule: subseq_finite_order_each_actual_adjacent_pair · Uses: G001, S010

S012 · implies

Before

ORIGINAL finite index list=[20, 21, 22, 23, 24, 25];ALL adjacent strict flags=[Yes, Yes, Yes, Yes, Yes]

After

this finite prefix increasing=Yes;INFINITE certificate supplied by original data=No;finite_prefix_not_infinite_subsequence_certificate

Conditions: none

The No says the original data do not specify a universal law for all later indices.A valid finite prefix can be separately extended,for example by adding1 after its last value,but that does not determine an unspecified original continuation.If the prefix already fails,its actual adjacent violation is the obstruction.

Step identifiers and dependencies

Rule: subseq_prefix_No_not_nonextendability_or_sorting · Uses: G001, S011

Reverse checks

  • S012 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 subsequence finite prefix adjacent index5 difference 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 — Recompute subsequence finite prefix adjacent index4 difference with exact rational arithmetic, not rounded decimals.
  • 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 — Recompute subsequence finite prefix adjacent index3 difference with exact rational arithmetic, not rounded decimals.
  • 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 — Recompute subsequence finite prefix adjacent index2 difference with exact rational arithmetic, not rounded decimals.
  • 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 subsequence finite prefix adjacent index1 difference 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

([20, 21, 22, 23, 24, 25], Yes, No, finite_increasing_prefix_not_infinite_subsequence_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: d6cc2037392b03fcd70db9592b0c2bf3497c3efc3d94ccca174cc3333efa96db
  • candidate record SHA-256: 4ce193340ab5c8f9ebe98e41f2b9e654dd4b7ec228fb25bbe57e5b1244aca34c
  • semantic review receipt SHA-256: 6e11e35fafe32f16900ce9b522d01acb7b2ee6b463ab179392076cfbe1af8034
  • question-first witness SHA-256: cc0fa361fc25151729e70264340d2eae94f179f6f2a2edfe80ba5704fbbd0682
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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