The optional sampling theorem for martingales indexed by a partially ordered set is true if the index set is directed. However, the corresponding result for submartingales indexed by a partially ...

With rapid advancement in data acquisition technology (i.e.analog-to-digital and digital-to-analog converters) and the explosive introduction of micro-computers, selected complex linear and nonlinear ...

This is a preview. Log in through your library . This monthly journal, begun in 1950, is devoted entirely to research in pure and applied mathematics, principally to the publication of original papers ...