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Step-Indexed Relational Reasoning for Countable Nondeterminism

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 نشر من قبل Lars Birkedal
 تاريخ النشر 2013
  مجال البحث الهندسة المعلوماتية
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 تأليف Lars Birkedal




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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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