 Most of the major AGM-related contraction operations have been generalized to multiple contraction: multiple partial meet contraction (Hansson 1989, Fuhrmann and Hansson 1994, Li 1998), multiple kernel contraction (Fermé et al. 2003), multiple specified meet contraction (Hansson 2010), and a multiple version of Grove’s sphere system (Reis and Fermé 2011, Fermé and Reis 2012).