Geographically if not temperamentally part of the Left Bank, the Palais-Bourbon is the seat of the Assemblee Nationale (parliament).
The Assemblee Nationale is the legislative branch of government.  
mnli hypothesis: The Assemblee Nationale is the legislative branch of government.   premise: Geographically if not temperamentally part of the Left Bank, the Palais-Bourbon is the seat of the Assemblee Nationale (parliament).