Explore related knowledge and questions →

Question 9338: An Explicit All-Input Linear Resource Witness

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 47

← Question derivation index · Original question batch

R0017-09338 · q-20261013-advance-20261019-r06-asymptotic-resource-bound-0063

Original question and givens

Use natural n≥0, nonnegative integers a=12, b=25, f(n)=a*n+b and g(n)=n+1 in a fixed cost model. Choose C=max(1,a+b), N=0. Give (a, b, C, N, witness valid?, the exact inequality a*n+b≤C*(n+1) for all n≥0).

  • G001 — Use natural n≥0, nonnegative integers a=12, b=25, f(n)=a*n+b and g(n)=n+1 in a fixed cost model. Choose C=max(1,a+b), N=0. Give (a, b, C, N, witness valid?, the exact inequality a*n+b≤C*(n+1) for all n≥0).

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

fixed cost model;explicit nonnegative functions on natural n

After

O,Omega and Theta quantify positive constants over a full tail

Conditions: none

Fix the cost model and function family first.O requires C>0 and N with an upper bound for every n≥N;Omega is the corresponding positive lower bound,and Theta requires both.Finite measurements describe only a finite window.

Step identifiers and dependencies

Rule: full_tail_not_finite_benchmark_scope · Uses: G001

S002 · calculation

Before

a+b for prescribed constant := sum(12, 25)

After

a+b for prescribed constant = 37

Conditions: none

Calculate exactly in the specified source-operand order without approximation or substituting a different candidate.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

C-a := sub(37, 12)

After

C-a = 25

Conditions: none

Calculate exactly in the specified source-operand order without approximation or substituting a different candidate.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

C-b := sub(37, 25)

After

C-b = 12

Conditions: none

Calculate exactly in the specified source-operand order without approximation or substituting a different candidate.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

a=12;b=25;C=max(1,a+b)=37;N=0

After

C(n+1)-(a*n+b)=(25)*n+(12)>=0 for every natural n

Conditions: none

C≥a and C≥b make both residual coefficients nonnegative for every natural n.This covers all n rather than selected points;when a=b=0,C=1 remains positive.

Step identifiers and dependencies

Rule: linear_all_input_nonnegative_residual · 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 — Recompute C-b with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute C-a with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute a+b for prescribed constant 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

(12, 25, 37, 0, Yes, 12n+25≤37(n+1) for all n≥0)

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: 8b8ca0ed5580b9a94f12f73736678d42569fa29f00a179132d7f17d301ad00d4
  • candidate record SHA-256: 1ebbe8f81b2bf97c0b6a198f0cd9019f6736d3b14639133a41128c6a5a3c0d72
  • semantic review receipt SHA-256: abad28564830bb9b6ef069ca5a1aa128ce7b1a67a5cb8fe6d868a06db73bcfb8
  • question-first witness SHA-256: 43126988479968837abe086263dac1b24c37463ad80e00d2e280a7b8e9036a04
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON