FAMIXAssociation is an abstract superclass for relationships between Famix named entities. It defines a polymorphic API refined by subclasses: essentially from, to, next and previous.

From and To properties are abstract at this level, but specific implementations can have multiple ends and properties. 

For example, FAMIXInheritance has:

(i) From mapped to the subclass;

(ii) To mapped to the superclass.

Next and Previous properties provide an order of the appearence of these associations in code. The order is calculated within a particular relationship for example, method invocation order within a calling method (from).

For example in java, the following code

 method a() { b(); c(); }

will produce two invocation associations first from method a to method b, and second from method a to method c. These associations are bound together and can be navigated with previous and next.