A congruence theorem for structured operational semantics of higher-order languages

2002 ◽  
Author(s):  
K.L. Bernstein
Keyword(s):  
Operational Semantics ◽  
Higher Order ◽  
Congruence Theorem

Principal signatures for higher-order program modules

1994 ◽  
Vol 4 (3) ◽  
pp. 285-335 ◽  
Author(s):  
Mads Tofte
Keyword(s):  
Programming Languages ◽  
Functional Programming ◽  
Operational Semantics ◽  
Higher Order ◽  
Principal Type ◽  
Functional Programming Languages ◽  
Standard Ml ◽  
Static Semantics ◽  
Program Modules

AbstractIn this paper we present a language for programming with higher-order modules. The language HML is based on Standard ML in that it provides structures, signatures and functors. In HML, functors can be declared inside structures and specified inside signatures; this is not possible in Standard ML. We present an operational semantics for the static semantics of HML signature expressions, with particular emphasis on the handling of sharing. As a justification for the semantics, we prove a theorem about the existence of principal signatures. This result is closely related to the existence of principal type schemes for functional programming languages with polymorphism.

Mechanizing proofs with logical relations – Kripke-style

2018 ◽  
Vol 28 (9) ◽  
pp. 1606-1638 ◽  
Author(s):  
ANDREW CAVE ◽  
BRIGITTE PIENTKA
Keyword(s):  
Case Studies ◽  
Operational Semantics ◽  
Lambda Calculus ◽  
Equational Theory ◽  
Higher Order ◽  
Abstract Syntax ◽  
Completeness Proof ◽  
Typed Lambda Calculus ◽  
Contextual Equivalence ◽  
The Right

Proofs with logical relations play a key role to establish rich properties such as normalization or contextual equivalence. They are also challenging to mechanize. In this paper, we describe two case studies using the proof environmentBeluga: First, we explain the mechanization of the weak normalization proof for the simply typed lambda-calculus; second, we outline how to mechanize the completeness proof of algorithmic equality for simply typed lambda-terms where we reason about logically equivalent terms. The development of these proofs inBelugarelies on three key ingredients: (1) we encode lambda-terms together with their typing rules, operational semantics, algorithmic and declarative equality using higher order abstract syntax (HOAS) thereby avoiding the need to manipulate and deal with binders, renaming and substitutions, (2) we take advantage ofBeluga's support for representing derivations that depend on assumptions and first-class contexts to directly state inductive properties such as logical relations and inductive proofs, (3) we exploitBeluga's rich equational theory for simultaneous substitutions; as a consequence, users do not need to establish and subsequently use substitution properties, and proofs are not cluttered with references to them. We believe these examples demonstrate thatBelugaprovides the right level of abstractions and primitives to mechanize challenging proofs using HOAS encodings. It also may serve as a valuable benchmark for other proof environments.

scholarly journals HOPLA--A Higher-Order Process Language

2002 ◽  
Vol 9 (49) ◽  
Author(s):  
Mikkel Nygaard ◽  
Glynn Winskel
Keyword(s):  
Operational Semantics ◽  
Lambda Calculus ◽  
Expressive Power ◽  
Higher Order ◽  
Domain Theory ◽  
Order Process ◽  
Encode Process ◽  
Mobile Ambients ◽  
Computation Path ◽  
Congruence Properties

A small but powerful language for higher-order nondeterministic processes is introduced. Its roots in a linear domain theory for concurrency are sketched though for the most part it lends itself to a more operational account. The language can be viewed as an extension of the lambda calculus with a ``prefixed sum'', in which types express the form of computation path of which a process is capable. Its operational semantics, bisimulation, congruence properties and expressive power are explored; in particular, it is shown how it can directly encode process languages such as CCS, CCS with process passing, and mobile ambients with public names.

scholarly journals New-HOPLA--A Higher-Order Process Language with Name Generation

2004 ◽  
Vol 11 (21) ◽  
Author(s):  
Glynn Winskel ◽  
Francesco Zappa Nardelli
Keyword(s):  
Operational Semantics ◽  
Expressive Power ◽  
Higher Order ◽  
Domain Theory ◽  
Process Algebras ◽  
Order Process ◽  
Pi Calculus ◽  
Mobile Ambients ◽  
Congruence Properties

This paper introduces new-HOPLA, a concise but powerful language for higher-order nondeterministic processes with name generation. Its origins as a metalanguage for domain theory are sketched but for the most part the paper concentrates on its operational semantics. The language is typed, the type of a process describing the shape of the computation paths it can perform. Its transition semantics, bisimulation, congruence properties and expressive power are explored. Encodings are given of well-known process algebras, including pi-calculus, Higher-Order pi-calculus and Mobile Ambients.

Typing and subtyping for mobile processes

1996 ◽  
Vol 6 (5) ◽  
pp. 409-453 ◽  
Author(s):  
Benjamin Pierce ◽  
Davide Sangiorgi
Keyword(s):  
Process Algebra ◽  
Operational Semantics ◽  
Type System ◽  
Higher Order ◽  
Order Process ◽  
Process Calculi ◽  
Mobile Processes

The π-calculus is a process algebra that supports mobility by focusing on the communication of channels. Milner's presentation of the π-calculus includes a type system assigning arities to channels and enforcing a corresponding discipline in their use. We extend Milner's language of types by distinguishing between the ability to read from a channel, the ability to write to a channel, and the ability both to read and to write. This refinement gives rise to a natural subtype relation similar to those studied in typed λ-calculi. The greater precision of our type discipline yields stronger versions of standard theorems on the π-calculus. These can be used, for example, to obtain the validity of β-reduction for the more efficient of Milner's encodings of the call-by-value λ-calculus, which fails in the ordinary π-calculus. We define the syntax, typing, subtyping, and operational semantics of our calculus, prove that the typing rules are sound, apply the system to Milner's λ-calculus encodings, and sketch extensions to higher-order process calculi and polymorphic typing.

scholarly journals A monadic analysis of information flow security with mutable state

2005 ◽  
Vol 15 (2) ◽  
pp. 249-291 ◽  
Author(s):  
KARL CRARY ◽  
ALEKSEY KLIGER ◽  
FRANK PFENNING
Keyword(s):  
Side Effects ◽  
Information Flow ◽  
Operational Semantics ◽  
Higher Order ◽  
Information Flow Security ◽  
Low Level ◽  
High Security ◽  
Mutable State ◽  
Security Levels ◽  
Typed Languages

We explore the logical underpinnings of higher-order, security-typed languages with mutable state. Our analysis is based on a logic of information flow derived from lax logic and the monadic metalanguage. Thus, our logic deals with mutation explicitly, with impurity reflected in the types, in contrast to most higher-order security-typed languages, which deal with mutation implicitly via side-effects. More importantly, we also take a store-oriented view of security, wherein security levels are associated with elements of the mutable store. This view matches closely with the operational semantics of low-level imperative languages where information flow is expressed by operations on the store. An interesting feature of our analysis lies in its treatment of upcalls (low-security computations that include high-security ones), employing an “informativeness” judgment indicating under what circumstances a type carries useful information.

scholarly journals Domain Theory for Concurrency

2003 ◽  
Vol 10 (43) ◽  
Author(s):  
Mikkel Nygaard ◽  
Glynn Winskel
Keyword(s):  
Linear Logic ◽  
Operational Semantics ◽  
Denotational Semantics ◽  
Higher Order ◽  
The Other ◽  
Domain Theory ◽  
Parallel Composition ◽  
Concurrent Computation ◽  
Contextual Equivalence

A simple domain theory for concurrency is presented. Based on a categorical model of linear logic and associated comonads, it highlights the role of linearity in concurrent computation. Two choices of comonad yield two expressive metalanguages for higher-order processes, both arising from canonical constructions in the model. Their denotational semantics are fully abstract with respect to contextual equivalence. One language derives from an exponential of linear logic; it supports a straightforward operational semantics with simple proofs of soundness and adequacy. The other choice of comonad yields a model of affine-linear logic, and a process language with a tensor operation to be understood as a parallel composition of independent processes. The domain theory can be generalised to presheaf models, providing a more refined treatment of nondeterministic branching. The article concludes with a discussion of a broader programme of research, towards a fully fledged domain theory for concurrency.

Contextual equivalence for inductive definitions with binders in higher order typed functional programming

2013 ◽  
Vol 23 (6) ◽  
pp. 658-700
Author(s):  
MATTHEW R. LAKIN ◽  
ANDREW M. PITTS
Keyword(s):  
Functional Programming ◽  
Operational Semantics ◽  
Higher Order ◽  
European Symposium ◽  
Proof Search ◽  
Inductive Definitions ◽  
University Of Cambridge ◽  
Meta Programming ◽  
Contextual Equivalence ◽  
Phd Thesis

AbstractCorrect handling of names and binders is an important issue in meta-programming. This paper presents an embedding of constraint logic programming into the αML functional programming language, which provides a provably correct means of implementing proof search computations over inductive definitions involving names and binders modulo α-equivalence. We show that the execution of proof search in the αML operational semantics is sound and complete with regard to the model-theoretic semantics of formulae, and develop a theory of contextual equivalence for the subclass of αML expressions which correspond to inductive definitions and formulae. In particular, we prove that αML expressions, which denote inductive definitions, are contextually equivalent precisely when those inductive definitions have the same model-theoretic semantics. This paper is a revised and extended version of the conference paper (Lakin, M. R. & Pitts, A. M. (2009) Resolving inductive definitions with binders in higher-order typed functional programming. InProceedings of the 18th European Symposium on Programming (ESOP 2009), Castagna, G. (ed), Lecture Notes in Computer Science, vol. 5502. Berlin, Germany: Springer-Verlag, pp. 47–61) and draws on material from the first author's PhD thesis (Lakin, M. R. (2010)An Executable Meta-Language for Inductive Definitions with Binders. University of Cambridge, UK).

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