from Europe with a valid entry visa. Umar Farouk Abdulmutallab's name should have come up on a computer screen.

VOA: standard.2009.12.28

Not by some very arcane numeric address inside my computer's memory, but by a symbol, by a name.

不是通过一些在我电脑内存中的神秘的数字地址,而是通过一个符号，一个名字。

哈佛公开课 - 计算机科学课程节选

Now, unlike high school math or in algebra Z where you call things X and Y and Z, in programming, in computer science, you're actually dealing with humans where it's useful to have a variable name that's more descriptive than X and Y and Z.

不像高中数学或者代数中,称为X和Y和，在程序设计和计算机科学里，你实际上是在和人打交道,在这里有个描述性比xyz更强的,变量名称是很重要的。

哈佛公开课 - 计算机科学课程节选