I have now released version 0.4 of the Probability library. As usual, it is available either from the Boost Vault (boost.probability-0.4.tar.gz) or from http://biology.nmsu.edu/software/probability/ The main difference from earlier versions is that a power function, pow(), is now available for both probability and likelihood types. In addition, several of the operators involving mixed domains or value types are handled correctly now, and the testing is even more thorough than before. More importantly, though, I have written a manuscript describing the motivation and conceptual framework for the library in greater detail than is given at the site above. I would welcome anyone who wishes to review the manuscript to do so. Please let me know and I will forward a copy. Finally, I would appreciate any comments on the existing code, compiler incompatibilities, etc. I think that this can be a valuable addition to Boost, and would like the feedback necessary to move it toward that goal. Cheers, Brook