Proposed resolution:

Change [rand.dist.samp.plinear] p. 10 as indicated:

10 Effects: Constructs a piecewise_linear_distribution object with parameters taken or calculated from the following values: Let b_k = xmin+k·δ for k = 0, . . . , n, and w_k = fw(b_k +δ) for k = 0, . . . , n.