The Constitution stipulates that the establishing of the constituencies or electoral colleges is governed by law, and that the elections are carried out by the system of proportional representation, as determined by the law. Concerning elections to the Senate, for which voters in the whole country are divided into two electoral colleges, the French electoral college and the Flemish electoral college, responsible for electing 15 and 25 senators respectively, voters from the constituency of Brussels-Hal-Vilvorde can vote for a Flemish list or a French-speaking list and thus belong, according to the choice made, to the one or the other college. Brussels-HalVilvorde is also a special constituency for the elections to the House of Representatives and to the European Parliament. Every province is a constituency for the House of Representatives, except Flemish Brabant (which includes the district of Hal-Vilvorde); the Belgian Court of Arbitration found this situation discriminatory in principle and asked the legislator to modify it. Finally, for both Chambers, voters from the two districts with linguistic facilities of Fourons and Comines-Warneton have the right to vote in a district situated on the other side of the linguistic border.