  One of the most difficult aspects of modeling complex dilemmas in
decision-analytic terms is composing a diagram of relevance relations from a
set of domain concepts. Decision models in domains such as medicine, however,
exhibit certain prototypical patterns that can guide the modeling process.
Medical concepts can be classified according to semantic types that have
characteristic positions and typical roles in an influence-diagram model. We
have developed a graph-grammar production system that uses such inherent
interrelationships among medical terms to facilitate the modeling of medical
decisions.

Artificial Intelligence