“…In contrast to the multitude of papers concerning regularization and C-stationarity conditions for infinite dimensional MPECs, see e.g., Friedman [1986], Bonnans and Tiba [1991], Bergounioux [1997], Bergounioux [1998], Bergounioux and Zidani [1999], Kunisch [2000, 2010], Hintermüller [2001Hintermüller [ , 2008, , , Zhu [2006], Farshbaf-Shaker [2011], there are fewer contributions which address the question of stricter optimality conditions. We refer to the classical paper of Mignot and Puel [1984], where the obstacle problem is discussed.…”