Comment by seanhunter

I'm pretty ambivalent about this and don't really think the rule is true as stated. It also just comes across as pretty smug. In my experience the preference for terse/verbose or noisy/"quiet" syntax is really down to individual taste and how much things are used, rather than a function of how new or expert a person is.

Since TFA mentions the walrus ":=" operator in python, as an example from another field, when you first learn maths, you might define a function as "f(x)=x^2 - 2" or whatever. Later on, you'll start to see people write ":=" for definitions such as the above and the plain "=" sign just where you have an equation so you are specifying a particular value rather than a definition (eg you might see "let f: R->R be f(x):= x^2-2. Find x such that f(x)=0").

However, some sources (especially in physics or some books on analysis[1]) use an equals sign with an equilateral triangle over it (like this "≜") to mean definitional equality (ie ":="). Now to me, coming from a computer science background, := for a definition seems very natural and ≜ seems super weird, but that really is just down to what you're used to.

And through it all, some people just use "=" everywhere.

This being mathematics, the author gets to choose whatever syntax they want and readers just have to cope as best they can. In computer languages, people go into huge amounts of bike shedding trying to force everyone else to use (or not use) a particular thing.

[1] Kevin Murphy's machine learning books use ≜