-lortensor::lortensor(lortensor_types const lt, string const & n, ex const & mu, ex const & nu, ex const & rho, ex const & sigma) : indexed(mu,nu,rho,sigma), type(lt), name(n)
+lortensor::lortensor(lortensor_types const lt, const string & n, const ex & mu, const ex & nu, const ex & rho, const ex & sigma) : indexed(mu,nu,rho,sigma), type(lt), name(n)