Freire, Elisabete RaposoMonteiro, Luís2014-01-132014-01-132009Freire, Elisabete; Monteiro, Luís. Defining Behaviours by Quasi-finality, In Formal Methods: Foundations and Applications, 290-305, ISBN: 978-3-642-10451-0. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009.978-3-642-10451-0 (Print)978-3-642-10452-7 (Online)http://hdl.handle.net/10400.3/258512th Brazilian Symposium on Formal Methods, SBMF 2009 Gramado, Brazil, August 19-21, 2009.This paper proposes a notion of quasi-final object for any concrete category, by relegating to the underlying category some of the requirements that final objects must satisfy in the main category. We present some very basic properties of quasi-final objects and show how known behaviours like traces and failures for transition systems, and behaviours extracted from the final sequence of an arbitrary endofunctor (here restricted to the first ω terms) can be described by quasi-final objects.engFormal Methods (Computer Science)Computer Softwarebook part2014-01-10