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Circular Coinduction in Coq Using Bisimulation-Up-To Techniques

  • Jörg Endrullis
  • Dimitri Hendriks
  • Martin Bodin
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7998)

Abstract

We investigate methods for proving equality of infinite objects using circular coinduction, a combination of coinduction with term rewriting, in the Coq proof assistant. In order to ensure productivity, Coq requires the corecursive construction of infinite objects to be guarded. However, guardedness forms a severe confinement for defining infinite objects, and this includes coinductive proof terms. In particular, circular coinduction is troublesome in Coq, since rewriting usually obstructs guardedness. Typically, applications of transitivity are in between the guard and the coinduction hypothesis. Other problems concern the use of lemmas, and rewriting under causal contexts. We show that the method of bisimulation-up-to allows for an elegant rendering of circular coinduction, and we use this to overcome the troubles with guardedness.

Keywords

Induction Hypothesis Recursive Call Proof Tree Proof Term Nonempty Word 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Jörg Endrullis
    • 1
  • Dimitri Hendriks
    • 1
  • Martin Bodin
    • 2
  1. 1.Department of Computer ScienceVU University AmsterdamThe Netherlands
  2. 2.INRIA Rennes & ENS LyonFrance

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