@math{f(t)} has a weight of approximately @math{1/e} at time @math{t+k},
approximately @am{1/e^2, 1/e**2} at time @am{t+2k, t+2*k}, and so on.
From the opposite direction, @math{f(t)} decays to weight @math{w} at
@math{f(t)} has a weight of approximately @math{1/e} at time @math{t+k},
approximately @am{1/e^2, 1/e**2} at time @am{t+2k, t+2*k}, and so on.
From the opposite direction, @math{f(t)} decays to weight @math{w} at