Correction (en bas) : « − d 2 d u i + 1 d x i + 1 + d 3 d u i + 1 d x i + 1 − … {\displaystyle -\operatorname {d} ^{2}{\frac {\operatorname {d} u_{i+1}}{\operatorname {d} x_{i+1}}}+\operatorname {d} ^{3}{\frac {\operatorname {d} u_{i+1}}{\operatorname {d} x_{i+1}}}-\ldots } » → « − d 2 d u i + 1 d x i + 2 + d 3 d u i + 1 d x i + 3 − … {\displaystyle -\operatorname {d} ^{2}{\frac {\operatorname {d} u_{i+1}}{\operatorname {d} x_{i+2}}}+\operatorname {d} ^{3}{\frac {\operatorname {d} u_{i+1}}{\operatorname {d} x_{i+3}}}-\ldots } » (coquille)