Explore related knowledge and questions →

Question 34046: Membership Including Closed Endpoints

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 171

← Question derivation index · Original question batch

R0067-34046 · q-20261005-advance-20261006-r01-order-relation-0071

Original question and givens

Under the usual real order, is (-20)/1 in the closed interval [-20, 22]? The denominator is positive and both endpoints are included.

  • G001 — Under the usual real order, is (-20)/1 in the closed interval [-20, 22]? The denominator is positive and both endpoints are included.

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 roles = [qf-order-closed-interval, [lower, operation, p, q, upper]]

After

derived = [closed_interval, no-invented-domain]

Conditions: none

Check THIS bank’s keys/operation/domain:legacy table underscores,MOD50 local hyphens;permissive BASE data acquires no unknown-field restriction.Keep Number.isInteger and SAFE source guards distinct,while preserving ORIGINAL JSON number representations.

Step identifiers and dependencies

Rule: R67_SOURCE_specific_keys_operation_domain_and_numeric_bank · Uses: G001

S002 · calculation

Before

Interval ORIGINAL lower times positive denominator := mul(-20, 1)

After

Interval ORIGINAL lower times positive denominator = -20

Conditions: none

Calculate exactly from ORIGINAL ordered operands.Legacy derived integers are not recapped at the RAW SAFE bound;MOD50 rationals separately retain the NAIVE pre-reduction source envelope.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

Interval ORIGINAL upper times positive denominator := mul(22, 1)

After

Interval ORIGINAL upper times positive denominator = 22

Conditions: none

Calculate exactly from ORIGINAL ordered operands.Legacy derived integers are not recapped at the RAW SAFE bound;MOD50 rationals separately retain the NAIVE pre-reduction source envelope.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · implies

Before

source roles = [-20, 1, -20, 22]

After

derived = [-20, -20, 22, Yes, Yes, Yes]

Conditions: none

For a positive denominator,lower≤p/q≤upper is equivalent to lower*q≤p≤upper*q.BOTH endpoints are included.A singleton is valid but contains only its endpoint.Do not use open inequalities or silently sort reversed endpoints.

Step identifiers and dependencies

Rule: Order_CLOSED_interval_BOTH_inclusive_inequalities · Uses: G001, S003

Reverse checks

  • S004 · premise_and_result_audit — Reverse-audit THIS step against the ORIGINAL roles,complete premises and field order.Distinguish implication from equivalence;preserve originals,English,MKOs,ASTs and review states.Finite checks are not independent review or general formal proof.
  • S003 · premise_and_result_audit — Recompute Interval ORIGINAL upper times positive denominator with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute Interval ORIGINAL lower times positive denominator with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Reverse-audit THIS step against the ORIGINAL roles,complete premises and field order.Distinguish implication from equivalence;preserve originals,English,MKOs,ASTs and review states.Finite checks are not independent review or general formal proof.

Result

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: a240b7d8a1564d4ea6b6964da3357408714a24073df3ae4122ba4db90d383fb1
  • candidate record SHA-256: ffeb21603e2dce14a6045ac4cce4163b60de173b176afa3e3917e665a322478e
  • semantic review receipt SHA-256: c89efa383b67bb2cf25bcf16160b9f5f614bbe5e5e791f4d7f58234d17a3371c
  • question-first witness SHA-256: 12766d451c5375842b4fc2843ae94807ec55f15763a916558026912a13873d57
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON