eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Leibniz International Proceedings in Informatics
1868-8969
2011-08-31
512
524
10.4230/LIPIcs.CSL.2011.512
article
Step-Indexed Relational Reasoning for Countable Nondeterminism
Schwinghammer, Jan
Birkedal, Lars
Programming languages with countable nondeterministic choice are computationally interesting since countable nondeterminism arises when modeling fairness for concurrent systems. Because countable choice introduces non-continuous behaviour, it is well-known that developing semantic models for programming languages with countable nondeterminism is challenging. We present a step-indexed logical relations model of a higher-order functional programming language with countable nondeterminism and demonstrate how it can be used to reason about contextually defined may- and must-equivalence. In earlier step-indexed models, the indices have been drawn from omega. Here the step-indexed relations for must-equivalence are indexed over an ordinal greater than omega.
https://drops.dagstuhl.de/storage/00lipics/lipics-vol012-csl2011/LIPIcs.CSL.2011.512/LIPIcs.CSL.2011.512.pdf
countable choice
lambda calculus
program equivalence