Hindley–Milner type system

E230805

polymorphic type system static type system type system

The Hindley–Milner type system is a classical polymorphic type system used in many functional programming languages, notable for enabling type inference without explicit type annotations.

Try in SPARQL Jump to: Surface forms Disambiguation Statements Elicitation Referenced by

All labels observed (7)

Label	Occurrences
Hindley–Milner type system canonical	11
Damas–Milner type system	3
Hindley–Milner polymorphic type system	1
Hindley–Milner type discipline	1
Hindley–Milner type inference	1
Item 5: Prefer auto to explicit type declarations	1
The Principal Type-Scheme of an Object in Combinatory Logic	1

How this entity was disambiguated

This entity first appeared as the object of triple T2092388 — 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: Hindley–Milner type system
Context triple: [Robin Milner, knownFor, Hindley–Milner type system]

A. Hoare logic
Hoare logic is a formal system in computer science used to reason rigorously about the correctness of computer programs using logical assertions about program states.
B. Haskell
Haskell is a statically typed, purely functional programming language known for its strong type system, lazy evaluation, and use in both academic research and industry.
C. Revised^n Report on the Algorithmic Language Scheme
The Revised^n Report on the Algorithmic Language Scheme is the series of formal documents that define and evolve the official specification of the Scheme programming language.
D. lambda calculus
Lambda calculus is a formal system in mathematical logic and computer science that uses function abstraction and application to investigate computation and serves as a foundational model for programming languages.
E. Church–Rosser property
The Church–Rosser property is a confluence property of rewriting systems stating that if an expression can be reduced in different ways, all reduction paths can be further reduced to a common equivalent form.
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: Hindley–Milner type system
Target entity description: The Hindley–Milner type system is a classical polymorphic type system used in many functional programming languages, notable for enabling type inference without explicit type annotations.

A. Hoare logic
Hoare logic is a formal system in computer science used to reason rigorously about the correctness of computer programs using logical assertions about program states.
B. Haskell
Haskell is a statically typed, purely functional programming language known for its strong type system, lazy evaluation, and use in both academic research and industry.
C. Revised^n Report on the Algorithmic Language Scheme
The Revised^n Report on the Algorithmic Language Scheme is the series of formal documents that define and evolve the official specification of the Scheme programming language.
D. lambda calculus
Lambda calculus is a formal system in mathematical logic and computer science that uses function abstraction and application to investigate computation and serves as a foundational model for programming languages.
E. Church–Rosser property
The Church–Rosser property is a confluence property of rewriting systems stating that if an expression can be reduced in different ways, all reduction paths can be further reduced to a common equivalent form.
F. None of above. chosen

Statements (50)

Predicate	Object
instanceOf	polymorphic type system ⓘ static type system ⓘ type system ⓘ
alsoKnownAs	Damas–Milner type system ⓘ linked to: Hindley–Milner type system HM type system ⓘ
appliedIn	functional programming languages ⓘ statically typed languages with type inference ⓘ
basedOn	lambda calculus ⓘ
coreConcept	generalization at let-bindings ⓘ monomorphic type variables in local bindings without let ⓘ most general unifier ⓘ unification-based type inference ⓘ
enables	type inference without explicit type annotations ⓘ
field	programming languages ⓘ type theory ⓘ
goal	assign principal types to all typable expressions ⓘ
hasAlgorithm	Algorithm J ⓘ Algorithm W ⓘ
hasFeature	completeness for its language fragment ⓘ let-polymorphism ⓘ parametric polymorphism ⓘ principal types ⓘ rank-1 polymorphism ⓘ soundness ⓘ type inference ⓘ
hasLimitation	does not support GADTs natively ⓘ does not support full higher-rank polymorphism ⓘ does not support type classes natively ⓘ
influenced	type system of Elm ⓘ type system of F# ⓘ type system of Haskell ⓘ type system of PureScript ⓘ type system of ReasonML ⓘ
namedAfter	J. Roger Hindley ⓘ Robin Milner ⓘ
property	decidable type inference ⓘ principal type property ⓘ
relatedTo	System F ⓘ simply typed lambda calculus ⓘ
restrictionOf	System F ⓘ
supports	polymorphic functions ⓘ type generalization ⓘ type instantiation ⓘ
typicalComplexity	polynomial time type inference ⓘ
usedIn	Haskell core type system ⓘ ML programming language family ⓘ linked to: ML Miranda programming language ⓘ OCaml ⓘ Standard ML ⓘ early versions of Haskell ⓘ

How these facts were elicited

Referenced by (19)

Full triples — surface form annotated when it differs from this entity's canonical label.

Robin Milner → knownFor → Hindley–Milner type system ⓘ

Standard ML → hasFeature → Hindley–Milner type system ⓘ

Hindley–Milner type system → alsoKnownAs → Damas–Milner type system ⓘ