function (gamma = 0.9) 
{
    weight.diff = c(6, 7, 5, 10.5, 8.5, 3.5, 6.1, 4, 4.6, 4.5, 
        5.9, 6.5)
    N = length(weight.diff)
    M = N * (N + 1)/2
    A = outer(weight.diff, weight.diff, "+")/2
    A.vec = sort(A[row(A) <= col(A)])
    i0 = qsignrank((1 - gamma)/2, N)
    if (psignrank(i0, N) == (1 - gamma)/2) 
        i0 = i0 + 1
    index = c(i0, M - i0 + 1)
    names(index) = c("i0", "M-i0+1")
    Interval = c(A.vec[i0], A.vec[M - i0 + 1])
    names(Interval) = c("Lower", "Upper")
    estimate = median(A.vec)
    names(estimate) = "HL-estimate"
    list(estimate = estimate, index = index, Interval = Interval, 
        achieved.confidence = 1 - 2 * psignrank(i0 - 1, N))
}