Let E be a Hausdorff topological vector space having a Schauder basis
{b(i)} and coordinate functionals {f(i)}. Let sigma(E, F) be the weak
topology on E induced by F = {f(i): i is an element of N}. We show tha
t if a series in E is subseries convergent with respect to sigma(E, F)
, then it is subseries convergent with respect to the original topolog
y of E.