
$$\halign{
\hfil$#$ & $= # \hfil $ & $+ #\hfil$ \cr
\int_0^\infty f(t) dt  & \int_0^M f(t) dt    & \int_M^\infty f(t) dt \cr
                       & \int_0^M e^{-kt} dt & \int_M^\infty (e^{-kM} + 1)e^{-k(t-M)} dt \cr
                      & {1 \over k }(1-e^{-kM}) & {1\over k}(e^{-kM} +  1)\cr
                      & \ldots & \omit \cr
}$$