In the literature it has so far been assumed, that constrained distributions are best sam-pled by rebuilding alias tables for the constrained probabilities p(I)| I∈|D i . This approach still uses the precomputed probabilities p(I) to obtain p(I)| I∈|D i , but ignores the already available alias tables for p(I). This is an unnecessary slowdown because the computational effort for reconstructing constrained alias tables scales linearly with the number of particles Note that the constant scaling with respect to system size is only one part of the story.