# Safety and Liveness Properties

During the execution, we will concern certain program properties, such as program correctness, program halt, no exceptions, etc. For those program properties one may interest in, it can be divided into two categories:

• Safety Properties, It will not step into unexpected state during program execution (such as call with unmatched parameters, array subscript out of bounds, etc.):
• Liveness Properties, The expected state will arrive during program execution eventually(such as halt, get resource request must return successfully, etc.).

The topology of program properties will be introduced below. Finally, for any program property, it can be decomposed into the intersection of its safety component and liveness component.

# Convolutions and the Fast Fourier Transform

In mathematics and, in particular, functional analysis, convolution is a mathematical operation on two functions f and g, producing a third function. Using the fast Fourier transform can implement discrete convolutions in $$O(nlogn)$$ time.

#if you are the interviewee of SYSU-MSTC, congratulations, you passed the first interview and then choose the fascinating topic about F# for your second interview.

Introduction to F#

# 你的第一个F#程序

#如果看到这篇文章的你是SYSU-MSTC的面试者，恭喜你通过了一面还选择了F#这个主题作为你二面的题目，这是一个超级有趣的选择。

# Who is Jose Martin?

This time, my new post is not about Computer Science, but it is about a song and a man.