We consider a Neumann problem driven by the (p, q)-Laplacian under the Landesman-Lazer type condition. Using the classical saddle point theorem and other classical results of the calculus of variations, we show that the problem has at least one nontrivial weak solution.

中文翻译：

---

Landesman-Lazer 型 (p, q)-Neumann 条件方程

我们考虑在 Landesman-Lazer 类型条件下由 (p, q)-Laplacian 驱动的 Neumann 问题。使用经典的鞍点定理和变分法的其他经典结果，我们表明该问题至少有一个非平凡的弱解。