CAS bug when calculating sum(1/n,n,1,medium_value)

[jte]

I've had a bit of fun playing around with this. One thing I was wondering was how a recursive definition would fare, a simple example being

f:=(a,b)->PIECEWISE(a = b,1/a,f(a,floor(((a+b)/2)))+f(floor(((a+b)/2))+1,b))

so that f(1,1000) would correspond to

Σ(1/x,x,1,1000)

Splitting in the middle may well be suboptimal; split choices will certainly affect computational efficiency (and may well influence whether the computation will stay within the bounds of the numerical fractions).