I have found the error, it's in the addition algorithm, line 93, default_impl.hpp. Swap these two lines: std::size_t n = std::min(u.size(), v.size()); w.resize(m, 0); so that it reads w.resize(m, 0); std::size_t n = std::min(u.size(), v.size()); then it all works correctly again (for now :) ) I'll try to come up with faster multiplication and division algorithms in the upcoming week, I'll upload a version of the library with the above error corrected when the faster versions of the algorithms are implemented. The division algorithm didn't contain the bugs of Knuth, I had already found them and gave a correct implementation. (well, at least with respect to _those_ bugs). best regards, Richard Peters From: "Joel Young" <jdy@cs.brown.edu>
I believe there is a numeric error in big_integer_0.3. I am working to isolate it to a single operation.
Ok. I have it isolated to a piece of test code: