Notationally, parantheses seem to be very popular. Almost too popular. The following is a collection of all the different notations that I've found paranthesis used for. If you would like to add one, send me a pull request on Github.
| Name | Usage | Locations (non-exhaustive) |
|---|---|---|
| Function application | The value f(2) is, oddly, ... | Mathematics, programming |
| Precedence | 2+(3⋅5)≠(2+3)⋅5 | Mathematics, programming |
| Parentheticals | The man (who wore flannel) began ... | Writing |
| Ideal | (N):={kN∣k∈Z} | Ring Theory |
| Tuples | (x,y)=(0.5,1.7) | Mathematics, programming |
| Indexing | item = my_list(i) | MATLAB |
| n-dimensional sequences | Consider the sequence (aij) ... | Mathematics |
| Multiplication | (5)(17)=85 | Mathematics |
| S-Expression | (f x y z) | Lisps |
| Interval notation | ...so for any x in [0,+∞) we have ... | Mathematics |
| n choose k | {n \choose k} = \frac{n!}{k!(n-k)!} | Mathematics |
| Matrices | I_2 := \left( \begin{matrix} 1 & 0 \\ 0 & 1 \end{matrix} \right) | Mathematics |
| Greatest common divisor | (a, b) := \mathit{gcd}(a, b) | Mathematics |
| Generator expression | (f(x) for x in li) | Python |
| Function shorthand | (+), (+2), (3*) | Haskell |
| Congruence | 5 \equiv 15\ (\text{mod } 10) | Mathematics |
| Labels | See example (B) or refer back to (II) to... | Writing |
| Unit | () | Haskell |
| Enumeration | Two things: 1) ...; and 2) ... | Writing |
| Emoticon | :) :( ;) :'( | Texting |
| Permutation Cycles | (1 3)(2)(4 6 5) | Mathematics |