Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:The balanced function g having optimal algebraic immunity introduced in [3] can be defined for every n as the Boolean function on F2n whose support equals {α; i = s, · · · , s+ 2n−1 − 1}, where s is an integer and α is a primitive element of F2n .
Category: