module sn6l
export Hser, Hpar

function Hser(p,q)
    hn=0.0;
    for k in q:-1:p
        hn+=1.0/k
    end
    return hn
end
function Hpar(p,q)
    if q-p<20000000
        return Hser(p,q)
    end
    c=trunc(p/2+q/2)
    r1=@spawn Hpar(p,c)
    r2=@spawn Hpar(c+1,q)
    return fetch(r1)+fetch(r2)
end

end