Urdi lemma
E311986
The Urdi lemma is a geometric theorem developed by the 13th-century astronomer Mu’ayyad al-Din al-Urdi that underpins non-Ptolemaic planetary models in medieval Islamic astronomy and later influenced Copernican astronomy.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Urdi lemma canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T2931339 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Urdi lemma Context triple: [Islamic astronomy, introducedConcept, Urdi lemma]
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A.
Slovo
Slovo is a surname most notably associated with South African anti-apartheid activist and politician Joe Slovo and his family.
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B.
LEM
LEM is the original abbreviation for the Apollo Lunar Module, the spacecraft used by NASA astronauts to land on and ascend from the Moon during the Apollo missions.
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C.
LEMD
LEMD is the ICAO airport code for Adolfo Suárez Madrid–Barajas Airport, the main international airport serving Madrid, Spain.
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D.
Uras
Uras is a Mesopotamian goddess associated with the earth and sometimes identified with the goddess Ki, known primarily as the consort of the sky god Anu.
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E.
Inuinnaqtun
Inuinnaqtun is an Inuit language spoken in parts of the Canadian Arctic, particularly in western Nunavut and the Northwest Territories.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Urdi lemma Target entity description: The Urdi lemma is a geometric theorem developed by the 13th-century astronomer Mu’ayyad al-Din al-Urdi that underpins non-Ptolemaic planetary models in medieval Islamic astronomy and later influenced Copernican astronomy.
-
A.
Slovo
Slovo is a surname most notably associated with South African anti-apartheid activist and politician Joe Slovo and his family.
-
B.
LEM
LEM is the original abbreviation for the Apollo Lunar Module, the spacecraft used by NASA astronauts to land on and ascend from the Moon during the Apollo missions.
-
C.
LEMD
LEMD is the ICAO airport code for Adolfo Suárez Madrid–Barajas Airport, the main international airport serving Madrid, Spain.
-
D.
Uras
Uras is a Mesopotamian goddess associated with the earth and sometimes identified with the goddess Ki, known primarily as the consort of the sky god Anu.
-
E.
Inuinnaqtun
Inuinnaqtun is an Inuit language spoken in parts of the Canadian Arctic, particularly in western Nunavut and the Northwest Territories.
- F. None of above. chosen
Statements (31)
| Predicate | Object |
|---|---|
| instanceOf |
geometric theorem
ⓘ
lemma ⓘ |
| appliesTo |
medieval Islamic astronomy
ⓘ
non-Ptolemaic planetary models ⓘ |
| describedIn | medieval Islamic astronomical treatises ⓘ |
| developer | Mu’ayyad al-Din al-Urdi ⓘ |
| field |
astronomy
ⓘ
geometry ⓘ history of astronomy ⓘ |
| hasContext |
geometrical transformations of circles
ⓘ
kinematic geometry ⓘ |
| hasDomain | mathematical astronomy ⓘ |
| hasEffect |
preserves uniform circular motion in models
ⓘ
supports non-Ptolemaic kinematic schemes ⓘ |
| hasRole | foundation of non-Ptolemaic planetary kinematics ⓘ |
| historicalPeriod | medieval period ⓘ |
| inception | 13th century ⓘ |
| influenced |
Copernican astronomy
ⓘ
Nicolaus Copernicus’s planetary constructions ⓘ |
| languageOfOriginalWork | Arabic ⓘ |
| mainSubject | planetary models ⓘ |
| namedAfter | Mu’ayyad al-Din al-Urdi ⓘ |
| notableFor |
impact on later European astronomy
ⓘ
role in the critique of Ptolemaic astronomy ⓘ |
| partOf |
Maragha observatory
ⓘ
surface form:
Maragha school of astronomy
|
| relatedTo |
Ibn al-Shatir planetary model
ⓘ
surface form:
Maragha planetary models
Ptolemaic system ⓘ
surface form:
Ptolemaic equant
Tusi couple ⓘ |
| usedFor |
constructing alternative planetary models
ⓘ
eliminating the equant ⓘ modifying Ptolemaic planetary models ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Urdi lemma Description of subject: The Urdi lemma is a geometric theorem developed by the 13th-century astronomer Mu’ayyad al-Din al-Urdi that underpins non-Ptolemaic planetary models in medieval Islamic astronomy and later influenced Copernican astronomy.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.