An invitation to Friendly Testing

We present a new testing semantics, called friendly testing, whose main property is thatthe induced preorder between processes fr is consistent with the conformance relation, andso 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 thatinternal actions are not allowed. However, in order to obtain the desired notion of friendlytesting this restriction is not enough and we also have to…