Explore related knowledge and questions →

Question 15792: A Symbolic Parameter Tail Controls Every Required CDF Gap

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

Return to catalogue page 79

← Question derivation index · Original question batch

R0030-15792 · q-20261014-advance-20261031-r03-convergence-in-distribution-0042

Original question and givens

Use the explicit Bernoulli symbolic family with interior limit p=1/2, 0<p<1, signed c=2/20, positive shift=18, and p_n=p+c/(n+shift) for every n≥1. The whole parameter tail must stay in [0,1]. The Bernoulli CDF is 0 below 0, 1−p on [0,1), and 1 at or above 1. With this interior limit its only jumps are at 0 and 1; the definition requires CDF convergence only at its continuity points. A chosen coupling is not required, and convergence in probability, almost surely or in Lp is not inferred. Keep exact reduced rationals, omitting /1 for integers. n=17, threshold=1/2. Give (n,threshold,absolute_gap,limit_CDF_continuity_point?,gap_tends_to_zero_at_every_limit_CDF_continuity_point).

  • G001 — Use the explicit Bernoulli symbolic family with interior limit p=1/2, 0<p<1, signed c=2/20, positive shift=18, and p_n=p+c/(n+shift) for every n≥1. The whole parameter tail must stay in [0,1]. The Bernoulli CDF is 0 below 0, 1−p on [0,1), and 1 at or above 1. With this interior limit its only jumps are at 0 and 1; the definition requires CDF convergence only at its continuity points. A chosen coupling is not required, and convergence in probability, almost surely or in Lp is not inferred. Keep exact reduced rationals, omitting /1 for integers. n=17, threshold=1/2. Give (n,threshold,absolute_gap,limit_CDF_continuity_point?,gap_tends_to_zero_at_every_limit_CDF_continuity_point).

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 · calculation

Before

interior Bernoulli limit mass at0 := sub(1, 1/2)

After

interior Bernoulli limit mass at0 = 1/2

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001

S002 · implies

Before

original limit parameter=[1, 2];reduced p=1/2;mass at0=1/2;mass at1=1/2

After

both endpoint masses positive;only limit-CDF jumps at0 and1;registered interior projection

Conditions: none

Honor the source English restriction0<p<1,so both jumps genuinely have positive mass.Although the raw oracle allows endpoint parameters,do not extend this continuity-point protocol to degenerate distributions;their jump sets require separate analysis.

Step identifiers and dependencies

Rule: Bernoulli_interior_English_guard_not_degenerate_jump_set · Uses: G001, S001

S003 · calculation

Before

Bernoulli first legal tail denominator := sum(1, 18)

After

Bernoulli first legal tail denominator = 19

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

Bernoulli first tail signed correction := div(1/10, 19)

After

Bernoulli first tail signed correction = 1/190

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

Bernoulli first legal parameter := sum(1/2, 1/190)

After

Bernoulli first legal parameter = 48/95

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · implies

Before

declared all-n family p_n=1/2+(1/10)/(n+18);n>=1;first parameter=48/95;limit=1/2

After

for every n>=1,lambda=(1+18)/(n+18) in(0,1];p_n=(1-lambda)*1/2+lambda*(48/95) in[0,1]

Conditions: none

The signed c may be positive,negative or zero.Every parameter is a convex combination of the first legal parameter and the limit,so their probability bounds cover the whole tail,not merely one displayed n.No chosen coupling is required for this family of distributions.

Step identifiers and dependencies

Rule: Bernoulli_whole_signed_parameter_tail_convex_combination · Uses: G001, S005

S007 · calculation

Before

Bernoulli selected tail denominator := sum(17, 18)

After

Bernoulli selected tail denominator = 35

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

Bernoulli selected signed correction := div(1/10, 35)

After

Bernoulli selected signed correction = 1/350

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

Bernoulli selected exact parameter := sum(1/2, 1/350)

After

Bernoulli selected exact parameter = 88/175

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

selected distribution one minus Bernoulli parameter := sub(1, 88/175)

After

selected distribution one minus Bernoulli parameter = 87/175

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

selected distribution:Bernoulli parameter=88/175;same exact threshold=1/2;CDF branch=0<=t<1

After

selected distribution exact CDF value=87/175

Conditions: none

A CDF is P(X≤t):at0 include mass1−p,and at1 include all mass.Use the same threshold branch for both CDFs.The continuity flag is distinct from equality of two finite-n values.

Step identifiers and dependencies

Rule: Bernoulli_CDF_same_threshold_including_endpoints · Uses: G001, S010

S012 · calculation

Before

limiting distribution one minus Bernoulli parameter := sub(1, 1/2)

After

limiting distribution one minus Bernoulli parameter = 1/2

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · implies

Before

limiting distribution:Bernoulli parameter=1/2;same exact threshold=1/2;CDF branch=0<=t<1

After

limiting distribution exact CDF value=1/2

Conditions: none

A CDF is P(X≤t):at0 include mass1−p,and at1 include all mass.Use the same threshold branch for both CDFs.The continuity flag is distinct from equality of two finite-n values.

Step identifiers and dependencies

Rule: Bernoulli_CDF_same_threshold_including_endpoints · Uses: G001, S012

S014 · calculation

Before

Bernoulli selected signed CDF difference := sub(87/175, 1/2)

After

Bernoulli selected signed CDF difference = -1/350

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · calculation

Before

Bernoulli negative CDF difference absolute value := mul(-1, -1/350)

After

Bernoulli negative CDF difference absolute value = 1/350

Conditions: none

Compute exactly from original roles and established intermediates,retaining indices,signs,denominators and the operation's carrier.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · implies

Before

selected signed CDF difference=-1/350;same threshold=1/2

After

exact absolute gap=1/350;limit CDF continuity point=Yes

Conditions: none

Negate a negative difference and otherwise retain it;the signed difference is not the absolute error.This family may converge at jumps too,the definition simply does not require that.

Step identifiers and dependencies

Rule: convdist_exact_absolute_gap_not_signed_difference · Uses: G001, S015

S017 · implies

Before

declared all-n parameters p_n=1/2+(1/10)/(n+18);same complete Bernoulli CDF formula

After

for every real t,gap=abs(1/10)/(n+18) on0<=t<1,and0 outside;for every epsilon>0 choose integer N>=1 with N+18>abs(1/10)/epsilon;then all n>=N give gap<epsilon

Conditions: none

On[0,1) the CDF difference is−c/(n+s),and elsewhere zero.For arbitrary epsilon,the Archimedean choice of N bounds every later n and hence every required continuity point.This uses the declared whole-tail formula,not extrapolation from samples,and asserts no coupling or stronger convergence.

Step identifiers and dependencies

Rule: convdist_symbolic_all_n_tail_not_finite_sample_extrapolation · Uses: G001, S016

Reverse checks

  • S017 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S016 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S015 · premise_and_result_audit — Recompute Bernoulli negative CDF difference absolute value with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Recompute Bernoulli selected signed CDF difference with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S012 · premise_and_result_audit — Recompute limiting distribution one minus Bernoulli parameter with exact rational arithmetic, not rounded decimals.
  • 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 selected distribution one minus Bernoulli parameter with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute Bernoulli selected exact parameter with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute Bernoulli selected signed correction with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute Bernoulli selected tail denominator with exact rational arithmetic, not rounded decimals.
  • 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 — Recompute Bernoulli first legal parameter with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Bernoulli first tail signed correction with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute Bernoulli first legal tail denominator with exact rational arithmetic, not rounded decimals.
  • 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 — Recompute interior Bernoulli limit mass at0 with exact rational arithmetic, not rounded decimals.

Result

(17, 1/2, 1/350, Yes, gap_tends_to_zero_at_every_limit_CDF_continuity_point)

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: dbf95fc37241ab641ea629eb77fa9f6e4830f549c07330985da8eb1d728940a8
  • candidate record SHA-256: ad50302ae168cbcce13fcf70678184df0c96602928347d302ae3f9217a1da4f5
  • semantic review receipt SHA-256: 73bc08066ffb1a81eacb2d4e288d03f522aeefd3949fa0d97da41b484ed737bc
  • question-first witness SHA-256: ac120452a208b257b8270f38351a09dcd832cdbc8d9db6b69933f83e43cc9336
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON