Thread: What symbol do they use to bracket square brackets? Is there any end it it?

The question is really weird, because i cant put what i want to ask in one question.

What i am trying to ask is

Primary brackets: when you want to show (x+y)-(x+y), you use (), may i ask what this name is? or is it just "bracket"?

Secondary brackets: when you want to group it up more [(x+y)-(x+y)]-[(x+y)-(x+y)], you use [], square brackets.

Tertiary brackets: when i try to group it up more, i use ?[(x+y)-(x+y)]-[(x+y)-(x+y)]?-?[(x+y)-(x+y)]-[(x+y)-(x+y)]?
what do i put at the question marks?

Do brackets stop at secondary? or are there more than that? If so, how many more are used officially?

Typically it goes like this: { [ ( ) ] } and if you need more grouping symbols you use whatever you want.
What I do instead is this: { [ ( ( ) ) ] }. In other words, the first layer is parenthesis. Then after that you use parenthesis again. Then more parenthesis will be confusing, so I use straight brackets, and then curly brackets.

Often braces are used. But it really doesn't matter and usage isn't all that consistent. If could just as well be larger font brackets for example. Or each echelon could be indicated using larger parentheses.

If you're a programmer, you just use all parentheses. (Look up a sample of Lisp code sometimes. It's been called a bowl full of toenail clippings.) Beyond the strict usages in programming though, there's no right or wrong answer. Use whatever looks good. (Except for < > which almost always mean something more specific depending on the context.)

okay thanks, but doesn't { and } have some special meanings in mathematics?

Originally Posted by RamenNoodles

okay thanks, but doesn't { and } have some special meanings in mathematics?

It has several uses: Brace -- from Wolfram MathWorld

1. To denote grouping of mathematical terms, usually as the outermost delimiter in a complex expression such as ,
2. To delineate a set, as in ,

are two of the most common (but YMMV).

Originally Posted by RamenNoodles

Tertiary brackets: when i try to group it up more, i use ?[(x+y)-(x+y)]-[(x+y)-(x+y)]?-?[(x+y)-(x+y)]-[(x+y)-(x+y)]?
what do i put at the question marks?

I normally just alternate between square and round brackets.

As well you might.........

In general there are no "rules" - take your choice merely to improve legibility (BTW if, for example, you choose to use nested (round) parentheses and left/right don't match, LaTex returns an error report)

However there are exceptions to the "your choice" rule (unless you are very specific about your novel notation)

One is the so-called Lie bracket, another is the Poisson bracket - but again you are free to choose if you are very explicit about your notation.

In general, notation in mathematics is arbitrary and always needs defining every time you open your mouth - a point that seems to have escaped some posters in Physics

Plain round parentheses are typical in research papers and math texts. If the expression is very complicated, there are probably better ways to write it.

Someone please ban this spammer.