HUGIN API Reference Manual. The “HUGIN API 7.8 Reference Manual” provides a reference for the C language Application Program Interface to the HUGIN system. However, brief descriptions of the Java and C++ versions are also provided (see Chapter 1). The present manual assumes familiarity with the methodology of Bayesian belief networks and (limited memory) influence diagrams (LIMIDs) as well as knowledge of the C programming language and programming concepts.