I think the first mail did not work (at least I did not receive my own mail which was sent to this address), so I try it again. ------------ hello, I have (simple) a question about using PPL 0.4: I cannot find how to convert a coefficient (of a constraint or generator) to the normal integer type. In my code I do the following; c1 is a constraint which is defined earlier in the code. Now I try to convert a coefficient with c1_int = mpz_get_si(c1.coefficient(Variable(0))) but this doesn't work, probably because the coefficient is not of the regular gmp format (c1_int is a standard integer) How can I convert coefficients to 'normal' integers (or double integers)? Thank you for your help! Martin Rohde Delft University of Technology Kramers Laboratorium voor Fysische Technologie Tel 0031 +152787084 Mail martin@klftfs01.tn.tudelft.nl