In some examples, a system creates a requirement including EPG selectors representing EPG pairs, a traffic selector, and a communication operator; determines that EPGs in distinct pairs are associated with different network contexts and, for each pair, which network context(s) contains associated policies; creates first data representing the pair, operator, and traffic selector; when only one network context contains the associated policies, creates second data representing a network model portion associated with the only network context and determines whether the first data is contained in the second data to yield a first check; when both network contexts contain the associated policies, also creates third data representing a network model portion associated with a second network context, and determines whether the first data is contained in the second and/or third data to yield a second check; and determines whether policies for the pairs comply with the requirement based on the checks.