[en] 1 - Description of program or function: LSQXY can be used to do curve fitting and data combination taking into account the uncertainties associated with independent variables. 2 - Method of solution: To take the uncertainties of independent variables X into account in the fitting, we consider X also being the parameters to be fitted and require the results of the fitting to satisfy the constraint condition: Y = f(X;C ). 3 - Restrictions on the complexity of the problem: The number of data pairs is limited to less than 100 and the number of the parameter to be fitted, C, less than 20. But these limitations are easily eliminated by adapting the code