Let G be a locally compact group, A a subalgebra of the measure algebra M(G), and A a family of Borel subsets of G that is closed under finite unions. In this paper, among other results, we find sufficient conditions on A, that imply A is a semi-topological algebra with respect to the strict topology βA. We also find necessary and sufficient conditions on G, that imply A is a topological algebra with respect to the strict topology βA, where A is a family of Borel subsets of G with finite Haar measure.
