Hi there, I am having a bit of trouble evaluating some multiple polylogarithms using the latest version of GiNaC. GiNaC is giving me a different response depending on whether I input the values as fractions or decimals. Specifically, I'm trying to find a floating point representation for Li({1,1,2}, {1+1/2*I, 1, 3/5 - 4/5*I}). I've tried this by running (in ginsh): evalf(Li({1,1,2}, {1+1/2*I, 1, 3/5 - 4/5*I})); but this seems to hang (I've run it for over 12 hours with no result). On the other hand, running evalf(Li({1,1,2}, {1+0.5*I, 1, 3/5 - 4/5*I})); gives an answer almost immediately. I've tried this using a C++ program (see attached) which behaves in the same way: no result using the fraction but an answer with no issues using a decimal number. These calculations have been run using GiNaC 1.7.0 (stable & from git) on ArchLinux. Please let me know if there is anything I should try. Peter PS: I tried sending this email from a different address but it said it was greylist - I apologise if I've sent this twice.