Triple

T3705447
Position Surface form Disambiguated ID Type / Status
Subject Mattapan High-Speed Line E80880 entity
Predicate connectsWith P37 FINISHED
Object Ashmont–Braintree branch of the Red Line
The Ashmont–Braintree branch of the Red Line is a major rapid transit corridor of Boston’s MBTA system, running south from downtown Boston to the suburbs of Ashmont and Braintree.
 E385302 NE FINISHED

How this triple was built (4 steps)

Every LLM step that produced this triple, in pipeline order — named-entity classification, the disambiguation choices (the exact options shown, with the pick highlighted), and the generated description. The batch + timestamp of each is in the Provenance table below.

NER Named-entity recognition gpt-5-mini
Instruction
Given a phrase, classify it is english named entity (e.g., persons, organizations, works of art) in Latin script, or not (e.g., literals, dates, URLs, verbose phrases). For disambiguation, the statement where the phrase occurs as object is also given. Please return a JSON object with `phrase` (string, the phrase being analyzed) and `is_ne` (boolean, indicating whether the phrase is a Named Entity).
Input
Phrase: Ashmont–Braintree branch of the Red Line | Statement: [Mattapan High-Speed Line, connectsWith, Ashmont–Braintree branch of the Red Line]
NED1 Entity disambiguation (via context triple) gpt-5-mini-2025-08-07 
Target entity: Ashmont–Braintree branch of the Red Line
Context triple: [Mattapan High-Speed Line, connectsWith, Ashmont–Braintree branch of the Red Line]
  • A. MBTA Green Line C branch
    The MBTA Green Line C branch is a light rail service in Boston and Brookline that runs primarily along Beacon Street, connecting Cleveland Circle to downtown Boston.
  • B. MBTA Green Line B branch
    The MBTA Green Line B branch is a light rail service in Boston that runs along Commonwealth Avenue, primarily serving Boston University and the Allston–Brighton neighborhoods.
  • C. Red Line and Mattapan Line
    Red Line and Mattapan Line are two interconnected public transit rail services in the Boston area’s MBTA system, with the Mattapan Line operating as a light rail/heritage trolley branch off the Red Line.
  • D. Green Line Medford/Tufts branch
    The Green Line Medford/Tufts branch is an extension of Boston’s MBTA Green Line light rail that serves the Medford area, including Tufts University, as part of the Green Line Extension project.
  • E. Green Line E branch
    The Green Line E branch is a light rail service of Boston's MBTA Green Line that runs from downtown through the Back Bay and Longwood Medical Area to Heath Street in Jamaica Plain.
  • F. None of above. chosen
  • G. Unsure - the case is ambiguous/there is not enough information to decide.
NEDg Description generation gpt-5.1
Instruction
Generate a one-sentence description of the target entity. 
You are given a context triple in the form (subject, predicate, object), where the object is the target entity. 
# Instructions
Use the triple to infer relevant information about the entity. Describe the entity based on what is most defining, well-known. 
Avoid repeating the information from the triple, unless really essential.
# Response Format
Return only the sentence: "Description: [one-sentence description of the target entity]"
Input
Entity: Ashmont–Braintree branch of the Red Line
Triple: [Mattapan High-Speed Line, connectsWith, Ashmont–Braintree branch of the Red Line]
Generated description
The Ashmont–Braintree branch of the Red Line is a major rapid transit corridor of Boston’s MBTA system, running south from downtown Boston to the suburbs of Ashmont and Braintree.
NED2 Entity disambiguation (via description) gpt-5-mini-2025-08-07 
Target entity: Ashmont–Braintree branch of the Red Line
Target entity description: The Ashmont–Braintree branch of the Red Line is a major rapid transit corridor of Boston’s MBTA system, running south from downtown Boston to the suburbs of Ashmont and Braintree.
  • A. MBTA Green Line C branch
    The MBTA Green Line C branch is a light rail service in Boston and Brookline that runs primarily along Beacon Street, connecting Cleveland Circle to downtown Boston.
  • B. MBTA Green Line B branch
    The MBTA Green Line B branch is a light rail service in Boston that runs along Commonwealth Avenue, primarily serving Boston University and the Allston–Brighton neighborhoods.
  • C. Red Line and Mattapan Line
    Red Line and Mattapan Line are two interconnected public transit rail services in the Boston area’s MBTA system, with the Mattapan Line operating as a light rail/heritage trolley branch off the Red Line.
  • D. Green Line Medford/Tufts branch
    The Green Line Medford/Tufts branch is an extension of Boston’s MBTA Green Line light rail that serves the Medford area, including Tufts University, as part of the Green Line Extension project.
  • E. Green Line E branch
    The Green Line E branch is a light rail service of Boston's MBTA Green Line that runs from downtown through the Back Bay and Longwood Medical Area to Heath Street in Jamaica Plain.
  • F. None of above. chosen

Provenance (5 batches)

The batch behind each pipeline step, in order, with when it ran. Timestamps are batch-level — stages were processed in waves, so the object chain (NER → NED1 → NEDg → NED2) reads in order, but predicate / elicitation batches can sit in a different wave.

Step Stage Batch ID Status When
creating Elicitation batch_69ad8b1793888190a5f70e4b21dc05a1 completed March 8, 2026, 2:43 p.m.
NER Named-entity recognition batch_69adc54bbfcc8190bec9c16e3749c3b1 completed March 8, 2026, 6:51 p.m.
NED1 Entity disambiguation (via context triple) batch_69b4e4e9959881908b29fd6c5e344169 completed March 14, 2026, 4:32 a.m.
NEDg Description generation batch_69b4e5dcec648190bd351ed8967a2e9d completed March 14, 2026, 4:36 a.m.
NED2 Entity disambiguation (via description) batch_69b4e63a79088190a0d640dc5170ded0 completed March 14, 2026, 4:38 a.m.
Created at: March 8, 2026, 3:33 p.m.