Published online by Cambridge University Press: 20 November 2018
A vector measure (countable additive set function with values in a Banachspace) on a field may be extended to a vector measure on the generated σ-field, under certain hypotheses. For example, the extension is establishedfor the bounded variation case [2, 5, 8], and there are more generalconditions under which the extension exists [ 1 ]. The above results have ashypotheses fairly strong boundedness conditions on the n o rm of the measureto be extended. In this paper we prove an extension theorem of the same typewith a restriction on the range, supposing further that the measure ismerely bounded. In fact a vector measure on a σ- field is bounded (III. 4. 5of [3]) but it is conceivable that a vector measure on a field could beunbounded.