Riemann Sum

http://en.wikipedia.org/wiki/Riemann_sum

For all ε > 0, there exists δ > 0 such that for any tagged partition x_0,...,x_n and t_0,...,t_{n-1} whose mesh is less than δ

    cp. epsilon-delta definition -> Cauchy definition (epsilon-delta)
       cp. Continuous function (topology)


cf.
topology 위상수학