Hilbert cube

例句：

1. 1. The Hilbert cube is a mathematical problem that has been studied for centuries.
   希尔伯特立方体是一个被研究了几个世纪的数学问题。
2. 2. The Hilbert cube is used in computer graphics to create smooth surfaces.
   希尔伯特立方体在计算机图形学中用于创建平滑的表面。
3. 3.The Hilbert cube is a famous example of the Poincaré conjecture.
   希尔伯特立方体是庞加莱猜想的一个著名例子。