Hello, is it possible to write ginac symbols and expressions into a file as binary format?? i've tried this but i get segmentation fault when printing the read variables. you can try this one file example to see the problem. it writes to example.dat as binary format, then reads from it as binary format too. //CODE #include <ginac/ginac.h> #include <iostream> #include <fstream> using namespace std; using namespace GiNaC; int main(){ //WRITE if(1){ symbol a("a"), b("b"); ex myExp = a*b; cout << "Original: Symbols are '" << a << "' and '" << b << "', myExp = " << myExp << endl; fstream fw; fw.open( "example.dat", ios::out|ios::binary ); if( fw.is_open() ){ fw.write( (char*)&a, sizeof(a) ); fw.write( (char*)&b, sizeof(b) ); fw.write( (char*)&myExp, sizeof(myExp) ); fw.close(); } else{ printf("Error Opening File for writing\n"); } } //READ (SHOULD NOT DEPEND OF WRITE CODE) if(1){ symbol ca, cb; ex copyExp; fstream fr; fr.open( "example.dat", ios::in|ios::binary ); if( fr.is_open() ){ fr.read( (char*)&ca, sizeof(ca) ); fr.read( (char*)&cb, sizeof(cb) ); fr.read( (char*)©Exp, sizeof(copyExp) ); fr.close(); cout << "Read from file: Symbols are '" << ca << "' and '" << cb << "' myExp = " << copyExp << endl; } else{ cout << "Error opening file for reading: does it exist?" << endl; } } return 1; } //CODE thanks in advance -- Cristobal <http://www.youtube.com/neoideo>