[TYPES] Terminology in operational semantics

[Arend Rensink]

I've one observation to add to those made before. In process algebra, 
structural operational semantics is a favoured way of defining the 
semantics of languages, but there the rules often define a small-step 
semantics which is *not* a reduction semantics, but instead is labelled 
  (or indexed) by an "observable". The observable typically stands for 
an interaction with the environment that is required in order for the 
step to proceed. This is a useful technique for defining a compositional 
semantics; the corresponding reduction, or whole-world, semantics, is 
obtained by adding in the environment.

-- 
Arend Rensink                         http://www.cs.utwente.nl/~rensink
Department of Computer Science             mailto:rensink at cs.utwente.nl
University of Twente                               tel: +31 53 489 4862
P.O. Box 217, NL-7500 AE Enschede, Netherlands     fax: +31 53 489 3247