From: Eustachius Hamamelis on
Let E be a Banach space. Let x be a countably additive E-valued
measure of finite variation vx on a (semi)ring S and ex its extension
to the sigma-ring R generated by S. Extend vx to a countably additive
measure evx on R. Let vex denote the variation of ex. Is vex=evx?


Eustachius