Hello, i failed to compile the sample from :http://www.ginac.de/tutorial/Input_002foutput.html#Input_002foutput on Ubuntu linux with gcc-4.4.0. #include <iostream> #include <string> #include <stdexcept> #include <ginac/ginac.h> using namespace std; using namespace GiNaC; int main() { cout << "Enter an expression containing 'x': " << flush; parser reader; try { ex e = reader(cin); symtab table = reader.get_syms(); symbol x = table.find("x") != table.end() ? ex_to<symbol>(table["x"]) : symbol("x"); cout << "The derivative of " << e << " with respect to x is "; cout << e.diff(x) << "." << endl; } catch (exception &p) { cerr << p.what() << endl; } } Do you have any suggestions, i used the following command line to compile the sample: g++ -o test test1.cpp -lginac $ g++ -o test test1.cpp -lginac test1.cpp: In function »int main()«: test1.cpp:11: Error: »parser« not declared in this scope test1.cpp:11: Error: expected »;« before »reader« test1.cpp:14: Error: »reader« not declared in this scope test1.cpp:15: Error: »symtab« not declared in this scope test1.cpp:15: Error: expected »;« before »table« test1.cpp:16: Error: »table« not declared in this scopedefiniert It looks like i missed some #include <ginac/parser.h> ??? Thanks in advance Martin -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01