... with some general remarks on isotonic splines. We shall reserve the symbol 0 for the differentiation operator and the symbol L 2 for the set of measurable square integrable functions on the interval =-=[0,1]-=-. The symbol W will denote the set of functions f on [0,1] for which Ojf m is absolutely continuous for j = O,l, ... ,m-l and Omf is in L 2 . When we occasionally consider functions with domain other ...