1. 31页，第一行
   
   应改成
   

2. 35 页， 正定矩阵的定义 （公式 2-15）
   标准正定矩阵的定义，应该没有 “对称矩阵” 这一条件吧？ 只是您在本书大多讨论的是“对称”正定矩阵，所以加上了 “对称” 这一条件？

3. 38页， 奇异值分解定义（公式 2-16）
   ![default](https://

Some containers aren't ready just when they open up their ports, for example postgres has a two-phase startup in which it will open the ports twice. We need to be able to add custom logic to ensure readiness in complex-to-check containers.

SVerchok and Eevee Nodes, what a great companion combo to m

Explain that this collection should be considered as entry-level exercises for beginners (something like tutorial examples in Processing website). Consider more funny for a beginner to take a look to the image and try to reproduce it without see the code.