TY  - JOUR
A1  - Kutzner, Arne
A1  - Schmidt-Schauß, Manfred
T1  - A non-deterministic call-by-need lambda calculus
T2  - Proceedings of the third ACM SIGPLAN international conference on Functional programming, Baltimore, Maryland, United States
N2  - In this paper we present a non-deterministic call-by-need (untyped) lambda calculus lambda nd with a constant choice and a let-syntax that models sharing. Our main result is that lambda nd has the nice operational properties of the standard lambda calculus: confluence on sets of expressions, and normal order reduction is sufficient to reach head normal form. Using a strong contextual equivalence we show correctness of several program transformations. In particular of lambdalifting using deterministic maximal free expressions. These results show that lambda nd is a new and also natural combination of non-determinism and lambda-calculus, which has a lot of opportunities for parallel evaluation. An intended application of lambda nd is as a foundation for compiling lazy functional programming languages with I/O based on direct calls. The set of correct program transformations can be rigorously distinguished from non-correct ones. All program transformations are permitted with the slight exception that for transformations like common subexpression elimination and lambda-lifting with maximal free expressions the involved subexpressions have to be deterministic ones.
Y1  - 1998
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/3471
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-19313
SP  - 324
EP  - 335
ER  -