Hi all, I'm fairly new to GiNaC, but it's most impressive so far. But I've a problem, I'm struggling to perform the following: I have a polynomial with lots of terms (beta,e,t1 & t2 are realsymbols) like: 1/6+1/36*e^(-beta)*e^t1*e^(-t1)+1/36*e^(-t1)*e^(-beta)*e^t1+ 25/36*e^t1*e^(-beta)*e^(-t1)-1/36*e^(-t1)-1/36*e^(-t1)- 1/36*e^t1*e^(-beta)-1/36*e^t1*e^(-beta)-1/36*e^(-beta)*e^t1+ 5/36*e^(-t1)-1/36*e^(-t1)+1/36*e^(-t1)*e^t1*e^(-beta)- 1/36*e^(-t1)+1/36*e^(-beta)*e^(-t1)*e^t1-1/36*e^(-beta)*e^t1- 1/36*e^(-beta)*e^t1+1/36*e^t1*e^(-t1)*e^(-beta)-1/36*e^(-t1)+ 5/36*e^t1*e^(-beta) which should simply evaluate to: 1/6+5/6*e^(-beta) I've not managed to make the expand() & collect() functions do this, it seems to not want to perform something like: e^t*e^(1-t)=e^1 I also tried this using actual exp() instead of e^ symbol, but I found it harder to collect terms then too. Is there something I'm missing or doing wrong? Many thanks in advance, -Gerry