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arXiv · 1310.2031

Step-Indexed Relational Reasoning for Countable Nondeterminism

Lars Birkedal·Aleš Bizjak·Jan Schwinghammer
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Abstract

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}.

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Lars Birkedal, Aleš Bizjak, Jan Schwinghammer. 2013-10-08. Step-Indexed Relational Reasoning for Countable Nondeterminism. https://doi.org/10.2168/lmcs-9(4%3A4)2013

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