                 maxRes = max(fabs(inf_cst), fabs(sup_cst));
                 maxMul = max(fabs(tmp1), fabs(tmp2));
 
-                inf_cst += tmp1 + (maxRes + maxMul)*ulp + min_denormal;
+                inf_cst += tmp1 - (maxRes + maxMul)*ulp - min_denormal;
                 sup_cst += tmp2 + (maxRes + maxMul)*ulp + min_denormal;
             }
         }

                                maxRes = max(fabs(inf_coeff), fabs(sup_coeff));
                                maxMul = max(fabs(tmp1), fabs(tmp2));

                                inf_coeff = inf_coeff + tmp1 + (maxRes + maxMul)*ulp;
                                sup_coeff = sup_coeff + tmp2 + (maxRes + maxMul)*ulp;
                            }
                        }

                                        maxRes = max(fabs(inf_coeff), fabs(sup_coeff));
                                        maxMul = max(fabs(tmp1), fabs(tmp2));

                                        inf_coeff = inf_coeff + tmp1 - (maxRes + maxMul)*ulp;
                                        sup_coeff = sup_coeff + tmp2 + (maxRes + maxMul)*ulp;
                                    }
                                }
