[GiNaC-list] 回复: issue about series involving positive symbol

I got a more compact case for this issue, by changing the in1 and in2 to ex in1 = reader("t^2/(3*m^2-t*m^2)/2"); ex in2 = reader("-(m^(-2)*(-3+t)^(-1)*t^2/2)"); sometimes we get the output: in1-in2 = 0 diff = 0 while, for some other times, we get the output: in1-in2 = 0 diff = 96*log(1/48) it seems that the sign of the log term has been changed. Best regards! Feng