  Using methods applied by Atiyah in equivariant K-theory, Bredon obtained
exact sequences for the relative cohomologies (with rational coefficients) of
the equivariant skeletons of (sufficiently nice) T-spaces, T=(S^1)^n, with free
equivariant cohomology over the cohomology of BT. Here we characterise those
finite T-CW complexes with connected isotropy groups for which an analogous
result holds with integral coefficients.
