An ordering linear unification algorithm

In this chapter, the authors apply type-theoretic techniques to the service description and composition verification. A flexible type system is introduced for modeling instances and mappings of semi-structured data, and is demonstrated to be effective in modeling a wide range of data services, ranging from relational database queries to web services for XML. Type-theoretic analysis and verification are then reduced to the problem of type unification. Some (in)tractability results of the unification problem and the expressiveness of their proposed type system are presented in this chapter. Finally, the auhtors construct a complete unification algorithm which runs in EXP-TIME in the worst case, but runs in polynomial time for a large family of unification problems rising from practical type analysis of service compositions.

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An annotated calculus and a unification algorithm

Rippling: Meta-Level Guidance for Mathematical Reasoning ◽

10.1017/cbo9780511543326.009 ◽

2005 ◽

pp. 177-189

Keyword(s):

Unification Algorithm

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A Nondeterministic Polynomial-Time Unification Algorithm for Bags, Sets and Trees

Lecture Notes in Computer Science - Foundations of Software Science and Computation Structures ◽

10.1007/3-540-49019-1_13 ◽

1999 ◽

pp. 180-196 ◽

Cited By ~ 6

Author(s):

Evgeny Dantsin ◽

Andrei Voronkov

Keyword(s):

Polynomial Time ◽

Unification Algorithm

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A Unification Algorithm for Associative-Commutative Functions

Journal of the ACM ◽

10.1145/322261.322262 ◽

1981 ◽

Vol 28 (3) ◽

pp. 423-434 ◽

Cited By ~ 182

Author(s):

Mark E. Stickel

Keyword(s):

Unification Algorithm

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A polynomial nominal unification algorithm

Theoretical Computer Science ◽

10.1016/j.tcs.2008.05.012 ◽

2008 ◽

Vol 403 (2-3) ◽

pp. 285-306 ◽

Cited By ~ 16

Author(s):

Christophe Calvès ◽

Maribel Fernández

Keyword(s):

Unification Algorithm

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Type Reconstruction for Type Classes

Journal of Functional Programming ◽

10.1017/s0956796800001325 ◽

1995 ◽

Vol 5 (2) ◽

pp. 201-224 ◽

Cited By ~ 12

Author(s):

Tobias Nipkow ◽

Christian Prehofer

Keyword(s):

Programming Language ◽

Functional Programming ◽

Type Inference ◽

Constraint Solving ◽

Simple Type ◽

Inference Problem ◽

Unification Algorithm ◽

Type Classes ◽

Type Reconstruction ◽

Inference Systems

AbstractWe study the type inference problem for a system with type classes as in the functional programming language Haskell. Type classes are an extension of ML-style polymorphism with overloading. We generalize Milner's work on polymorphism by introducing a separate context constraining the type variables in a typing judgement. This leads to simple type inference systems and algorithms which closely resemble those for ML. In particular, we present a new unification algorithm which is an extension of syntactic unification with constraint solving. The existence of principal types follows from an analysis of this unification algorithm.

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