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Question 34988: First Projection of a Binary Relation

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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← Question derivation index · Original question batch

R0068-34988 · q-20261003-advance-20261004-r03-relation-0038

Original question and givens

The binary relation has source A={0, 1, 2}, target B={4, 5, 6}, and R=∅⊆A×B. List its actual domain Dom(R) in increasing order with each element once.

  • G001 — The binary relation has source A={0, 1, 2}, target B={4, 5, 6}, and R=∅⊆A×B. List its actual domain Dom(R) in increasing order with each element once.

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-relation-domain-projection, [A, B, R, operation]]

After

derived = [domain_projection, no-invented-domain]

Conditions: none

Separate source banks:legacy RAW SAFE with unbounded derived BigInts versus BASE Number.isInteger without invented SAFE/million caps.Operations,domains and permissive/exact keys follow THIS bank.Keep ORIGINAL JSON intact.

Step identifiers and dependencies

Rule: R68_BANK_specific_keys_operations_and_numeric_guards · Uses: G001

S002 · implies

Before

source roles = [relation ORIGINAL source A, [0, 1, 2]]

After

derived = [[0, 1, 2]]

Conditions: none

THIS LDL set has0..100 DISTINCT RAW SAFE labels,with the empty set allowed.Sort only the derived representation;preserve original JSON order.Do not import another BASE set protocol.

Step identifiers and dependencies

Rule: LDL_RAW_distinct_SAFE_set_empty_allowed · Uses: G001, S001

S003 · implies

Before

source roles = [relation ORIGINAL target B, [4, 5, 6]]

After

derived = [[4, 5, 6]]

Conditions: none

THIS LDL set has0..100 DISTINCT RAW SAFE labels,with the empty set allowed.Sort only the derived representation;preserve original JSON order.Do not import another BASE set protocol.

Step identifiers and dependencies

Rule: LDL_RAW_distinct_SAFE_set_empty_allowed · Uses: G001, S002

S004 · implies

Before

source roles = [[0, 1, 2], [4, 5, 6], []]

After

derived = [Yes]

Conditions: none

FIRST qualify the COMPLETE R⊆A×B.A relation need not be total,single-valued,injective or onto.Empty R/carriers are allowed when typed.Keep ORIGINAL raw duplicates/order in the source copy.

Step identifiers and dependencies

Rule: Relation_COMPLETE_typed_subset_A_cross_B_NO_function_assumption · Uses: G001, S003

S005 · implies

Before

source roles = [[0, 1, 2], [4, 5, 6], []]

After

derived = [[], ∅]

Conditions: none

Dom(R)collects ONLY first coordinates ACTUALLY appearing in pairs,once each.A may contain unused elements,so do not simply return A.Empty R has empty domain.

Step identifiers and dependencies

Rule: Relation_DOMAIN_actual_FIRST_coordinates_not_declared_A · Uses: G001, S004

Reverse checks

  • S005 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S004 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S003 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S002 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S001 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.

Result

∅

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: f3b508b719bd54ab7e4454601b42a5d7abf342d181a34e78c5763b67ecbd833a
  • candidate record SHA-256: 71c2380032c0c915d029276cb37dc3f9dbbf47432144bfde66caefcef897d8c4
  • semantic review receipt SHA-256: e7a54104fa02c235f7591329bd6db8d626dd74bf0fae29c557b1f269c85066ed
  • question-first witness SHA-256: 8401a3c2064c1275a6a7ea8f00412fa12286cec7b2db6c305ff9dba3724ae229
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON