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cal implementations, the starting point used here involves the requirements on information flows. The 
focus is on the identification of requirements which the functions place on their respective Input informa 
tion. For the purpose of formulating the requirements, a methodology is used which is based on forms. 
Furthermore, categorisation of the test requirements is undertaken. 
The forms contained in Part C may be used as check lists in the testing of integrated navigation sys 
tems. The functional approach presented in the course of this report, for describing and testing this 
system, can thus be converted directly into practice.