The 20th WADT 2010 is put into perspective by giving afterglows of the 1st WADT 1982 in Langscheid near Dortmund, and the 10th WADT 1994 in Santa Margherita near Genova. First encounters with pioneers in the field are recalled, in particular with the ADJ group who initiated the initial-algebra approach. The author’s contributions at that time are put in this context. Around 1982, the emphasis of his work moved to databases and information systems, in particular conceptual modeling. His group used a triple of layers to model information systems, data—objects—systems, where the focus of interest now was on objects and systems. The interest in data issues paled in comparison. There were cases, however, where benefits could be drawn from the early work on ADTs and the foundations established in this field.


Isomorphism Class Operational Semantic Domain Equation Abstract Data Type Initial Algebra 
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© IFIP International Federation for Information Processing 2012

Authors and Affiliations

  • Hans-Dieter Ehrich
    • 1
  1. 1.Institut für InformationssystemeTechnische Universität BraunschweigBraunschweigGermany

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