\displaystyle \sum_{J\in\mathbb{P}; J\neq\emptyset}(f((\xi_K)_{K\in\mathbb{P}}(J))|J|)-\sum_{J\in\mathbb{P}; J\neq\emptyset}(\inf_{x\in J}f(x))|J|\leqslant\frac{1}{4}\varepsilon