The Legislative Assembly of the Federal District is formed, as it is the case in all legislatures in Mexico, by both single-seat and proportional seats, making it a system of parallel voting. The Federal District is divided into 40 electoral constituencies of similar population which elect one representative by first-past-the-post plurality (FPP), locally called "uninominal deputies". The Federal District as a whole constitutes a single constituency for the parallel election of 26 representatives by proportionality (PR) with open-party lists, locally called "plurinominal deputies".