Dear All, I have an issue with exhashmap, namely repeated erasing-insertion of elements eventually become trapped in an infinite loop in lines 487-491 of hash_map.h. Here is a sample code: #include <ginac/ginac.h> using namespace GiNaC; int main() { exhashmap<ex> M; M[realsymbol("x")] =1; int N= 30; for (int i =0; i < N; ++i ) { realsymbol a("a"); M[a]=numeric(i); M.erase(a); } return 0; } With this value of N the infinite loop appears on my computer with a probability around 40%. With larger values of N an infinite loop is almost certain. Did I miss something? Best wishes, Vladimir PS Also just to check that my patch for archiving empty lists from Sep 10 is not lost. -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/ Jupyter (Colab): https://github.com/vvkisil/MoebInv-notebooks Jupyter (CodeOcean): http://doi.org/10.24433/CO.9934595.v3