Hello, First I have a bug report: inifcns.cpp, function Order_eval, l.382, O(c)=O(1) is not true if c=0 hence the code slice should be ... if (is_ex_exactly_of_type(x, numeric)) { // O(c)=O(1) BUG! except if c=0, O(0)=0 if (x==0) return(x); else return Order(_ex1()).hold(); } else if (is_ex_exactly_of_type(x, mul)) { ... I am currently working on an implementation on polynomial arithmetic using tensors to represent multivariate polynomials instead of ex, in order to be more efficient. If people are interested, they can get http://perso.wanadoo.fr/bernard.parisse/ginac.tgz The current version implements GCD (gcdheu and sub-resultant algorithm) as well as extended GCD. Simplification might be much faster using test1.cc than the built-in normal function of GiNaC, for example if you try test1.cc on input like 1/x+1/(x-1)+1/(x-2)+...+1/(x-10) The archive should be untarred in the GiNaC-0.6.3 directory, it contains 3 modified GiNaC 0.6.3 files: inifcns.cpp (bug above fixed) power.h (members basis and exponent declared public to be used by qnormal.cc) expairseq.h (member epvector declared public). The other files are index.h/index.cc: index class to represent the powers of the variables in a monomial tensor.h: template class for multivariate polynomials of a given field qnormal.h/qnormal.cc: instantiation of tensor.h with numeric coeff test1.cc: test the simplification function test2.cc: instantiation and test of the extended GCD algorithm. Each file can be compiled by the compile command inside emacs. Best regards, Bernard Parisse, Institut Fourier, 100 rue des maths, Universite de Grenoble I, F-38402 St Martin d'Hères