An anecdotal introduction of the role of operational definitions in representing uncertainty is followed by a brief history of operational definitions, with particular attention to the foundations of probability and the fuzzy representations of uncertainty. A short summary of experience at the TU Delft points to relevant open questions. These in turn are illustrated by a recent application to N...

Compiled knowledge, which allows macro inference steps through an explanation space, can enable explanation-based learning (EBL) systems to reason efficiently in complex domains. Without this knowledge, the explanation of goal concepts is not generally feasible; moreover, the problem of finding the most general operational concept definition is intractable. Unfortunately, the use of compiled kn...

The aim of this paper is to give motivations for the development of operational semantics in membrane computing, and to survey existing proposals. In particular, the definitions are compared of three operational semantics available in the literature, namely a semantics proposed by Andrei, Ciobanu and Lucanu, another proposed by Busi, and another one proposed by the authors of the present paper....