President's Report/Rapport du Président

Ecole Normale Supérieure de Cachan 61 , avenue du Président Wilson 94235 Cachan Cedex France

Well-structured transition systems (WSTS's) are a general class of innnite state systems for which decidability results rely on the existence of a well-quasi-ordering between states that is compatible with the transitions. In this article, we provide an extensive treatment of the WSTS idea and show several new results. Our improved deenitions allow many examples of classical systems to be seen ...

Jean-Pierre Ramis, président,

Presidents, Vice Presidents, and Death: Closing the Constitution's Succession Gap

Éditorial: Lettre ouverte, pieds mouillés, au Président

Underwriting the presidents.

The United States has had 43 presidents. We examined whether they survive significantly longer or shorter than their contemporaries. We found that survival was better for presidents elected in the 1789-1841 and 1933-2001 periods (SMRs of 0.7 and 0.6, respectively), but worse for those elected in 1845-1929 (SMR = 2.9). We also found increased mortality during the years lived in office (SMR = 1.4...