some image logo

HOME

SEARCH

CURRENT ISSUE

REGULAR ISSUES

   Volume 1 (2005)

   Volume 2 (2006)

   Volume 3 (2007)

   Volume 4 (2008)

   Volume 5 (2009)

   Volume 6 (2010)

   Volume 7 (2011)

   Volume 8 (2012)

   Volume 9 (2013)

   Volume 10 (2014)

   Volume 11 (2015)

      Issue 1

      Issue 2

      Issue 3

      Issue 4

   Volume 12 (2016)

   Volume 13 (2017)

SPECIAL ISSUES

SURVEY ARTICLES

AUTHORS

ABOUT

SERVICE

LOGIN

FAQ

SUPPORT

CONTACT

VOLUME 11, ISSUE 1, PAPER 1


A Hoare logic for the coinductive trace-based big-step semantics of While

©Keiko Nakata, Institute of Cybernetics
©Tarmo Uustalu, Institute of Cybernetics

Abstract
In search for a foundational framework for reasoning about observable behavior of programs that may not terminate, we have previously devised a trace-based big-step semantics for While. In this semantics, both traces and evaluation (relating initial states of program runs to traces they produce) are defined coinductively. On terminating runs, this semantics agrees with the standard inductive state-based semantics. Here we present a Hoare logic counterpart of our coinductive trace-based semantics and prove it sound and complete. Our logic subsumes the standard partial-correctness state-based Hoare logic as well as the total-correctness variation: they are embeddable. In the converse direction, projections can be constructed: a derivation of a Hoare triple in our trace-based logic can be translated into a derivation in the state-based logic of a translated, weaker Hoare triple. Since we work with a constructive underlying logic, the range of program properties we can reason about has a fine structure; in particular, we can distinguish between termination and nondivergence, e.g., unbounded classically total search fails to be terminating, but is nonetheless nondivergent. Our meta-theory is entirely constructive as well, and we have formalized it in Coq.

Publication date: February 12, 2015

Full Text: PDF | PostScript
DOI: 10.2168/LMCS-11(1:1)2015

Hit Counts: 4979

Creative Commons