1 This volume contains the research papers and invited papers presented at the Third
International Conference on Tests and Proofs (TAP 2009) held at ETH Zurich Switzerland during
July 2-3 2009. TheTAPconferenceisdevotedtotheconvergenceofproofsandtests. Itc- bines
ideasfromboth sidesforthe advancementofsoftwarequality. Toprovethe correctness of a program is
to demonstrate through impeccable mathematical techniques that it has no bugs to test a
program is to run it with the exp- tation of discovering bugs. The two techniques seem
contradictory: if you have proved your program it is fruitless to comb it for bugs and if you
are testing it that is surely a sign that you have given up on any hope of proving its corre-
ness. Accordingly proofs and tests have since the onset of software engineering research been
pursuedby distinct communities using ratherdi?erent techniques and tools. And yet the
development of both approaches leads to the discovery of common issues and to the realization
that each may need the other. The emergence of model checking has been one of the ?rst signs
that contradiction may yield to complementarity but in the past few years an increasing number
of research e?orts have encountered the need for combining proofs and tests dropping earlier
dogmatic views of incompatibility and taking instead the best of what each of these software
engineering domains has to o?er.
