An invitation to friendly testing

Abstract

We present a new testing semantics, called friendly testing, whose main property is that the induced preorder between processes ⊑fr is consistent with the conformance relation, and so we have, for instance,a ⊕b ⊑fr a ⊑fr a +b. The new theory is strongly based on De Nicola & Hennessy’s work on testing. Friendly tests are defined exactly as in their work, except that internal actions are not allowed. However, in order to obtain the desired notion of friendly testing this restriction is not enough and we also have to relax the conditions to pass a test. Thus we obtain a new testing semantics and a new preorder between processes which is strictly weaker than the relation ⊑must. Moreover, we present an alternative characterization of our new testing semantics by defining a modification of acceptance sets.