“…In recent years there has been considerable interest in the study of geometric properties of the space P( k E). It has been shown not to be strictly convex [13], extremal and smooth points of the unit ball have been characterised for a number of spaces ( [3], [4], [5], [6], [7], [8], [9], [10]), and related problems have been considered, often in the finite-dimensional setting ( [1], [2], [11], [12]).…”