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arXiv · 1703.05121

Auxiliary Variables in TLA+

Leslie Lamport·Stephan Merz
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Abstract

Auxiliary variables are often needed for verifying that an implementation is correct with respect to a higher-level specification. They augment the formal description of the implementation without changing its semantics--that is, the set of behaviors that it describes. This paper explains rules for adding history, prophecy, and stuttering variables to TLA+ specifications, ensuring that the augmented specification is equivalent to the original one. The rules are explained with toy examples, and they are used to verify the correctness of a simplified version of a snapshot algorithm due to Afek et al.

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Leslie Lamport, Stephan Merz. 2017-03-15. Auxiliary Variables in TLA+. https://arxiv.org/abs/1703.05121

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