(sigemb-info 432) Talk by Susumu Nishimura (Dept. Math., Kyoto U), Thursday 9 July

[Ichiro Hasuo <ichiro@xxxxxxxxxxxxxxxxxxxx>]

Dear colleagues,

On the coming Thursday at 11.00am our colleague Susumu
Nishimura is giving a talk about his recent result on program logic.
No registration necessary. See you there!

Best regards,
Ichiro Hasuo
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RIMS-CS website
http://www.kurims.kyoto-u.ac.jp/~cs/

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Susumu Nishimura (Dept. Math., Kyoto U)
Refining Exceptions in Four-Valued Logic
11.00 - 12.00, Tuesday 9 July 2009
CS Laboratory, RIMS, Kyoto University
(See http://www.kurims.kyoto-u.ac.jp/~cs/lab.html for direction)

Abstract:
We discuss refinement of programs featuring exception
mechanisms and develop a refinement framework based on Arieli
and Avron's four-valued logic.  We show that exception features,
and other standard programming features as well, are naturally
expressed by a class of four-valued predicate transformers. The
resulting framework enjoys several refinement laws that are
useful for stepwise refinement of programs involving exception
handling and partial predicates.  We show a few examples of
transformation of programs, by which we demonstrate some typical
usages of the refinement laws in the proposed framework.