Hey Guys! Thanks again for your help. After realising that my system doesn't have a general solution, I thought about my problem again (actually that problem occured on my physics exercise sheet) and tried a completely different attempt and it worked :-) I also learned a lot using maple, great! Stephan

Hey Acer,

Thanks a lot, I will check that out first thing tomorrow at university! Looks great, way clearer than the stuff I wrote. As a beginner I just copied atttempts from some websites, hoping it would work :-)

Concerning my first attempt: I did not, at first, understand what you meant when mentioning a zero vector, until I saw that I forgot this:

b:=<exp(2*B*J_1+B*J_2),1,1,1,1,exp(-2*B*J_1+B*J_2),exp(2*B*J_1-B*J_2),exp(-2*B*J_1-B*J_2),exp(-2*B*J_1-B*J_2),exp(2*B*J_1-B*J_2),exp(-2*B*J_1+B*J_2),1,1,1,1,exp(2*B*J_1+B*J_2)>;

Must have gone lost while using Paste & Copy...Hmmm, I still wonder what is wrong then in my first attempt.
Greets!

Stephan