Dear All, I am compiling GiNaC v1.8.6 on Windows using MinGW from Qt distribution pack. The compilation stopped with the error: factor.cpp:2397:75: error: ambiguous overload for 'operator=' (operand types are 'GiNaC::numeric' and 'long long unsigned int') 2397 | ctx.modulus = (ctx.vnlst.size() > 3) ? ctx.vnlst.size() : 3; | ^ I was able to finish the compilation by replacing the line with: ctx.modulus = (ctx.vnlst.size() > 3) ? ctx.vnlst.size() : numeric(3); Just in case I am attaching this as patch. Best wishes, Vladimir -- Vladimir V. Kisil http://www1.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Maps https://doi.org/10.1142/p835 Soft: Geometry of cycles http://moebinv.sourceforge.net/ Jupyter notebooks: https://github.com/vvkisil?tab=repositories