A note on the superadditive and the subadditive transformations of   aggregation functions
  We expand the theoretical background of the recently introduced superadditive and subadditive transformations of aggregation functions $A$. Necessary and sufficient conditions ensuring that a transformation of a proper aggregation function is again proper are deeply studied and exemplified. Relationships between these transformations are also studied. 
Alexandra \v{S}ipo\v{s}ov\'a
math.FA