We extend Geisser and Hesselholt's result on "bi-relative K-theory"
from discrete rings to connective ring
spectra. That is, if A is a homotopy cartesian n-cube of
ring spectra (satisfying connectivity hypotheses), then the (n+1)-cube
induced by the
Homology, Homotopy and Applications, Vol. 10 (2008), No. 1, pp.29-39.
Available as: dvi dvi.gz ps ps.gz pdf