#include #include #include using std::cout; using std::endl; using std::string; using namespace lemon; int main() { Expr b; cout << b << endl; Expr c("f"); cout << c << endl; Expr d=8.0*string("g"); cout << d << endl; c*=5; cout << c << endl; Expr e=c; e+=8.9*9.0*string("l"); cout << e << endl; cout << c+d << endl; }