If you’ve ever wondered when to favor parentheses over square brackets and when to stick in a pair of curly braces, listen on. Parentheses. You’re probably well versed in how to use those sideways eyebrow thingies, better known as parentheses. First, remember that a pair of them is called “parentheses,” whereas a single one is a “parenthesis.” You may want to review episode 222 in which we compared parentheses to dashes and commas.
Garner's Modern American Usage has this on nested parentheses under an entry for square brackets ([ ]): brackets often show parentheses within parentheses Smith and her commander (Robert Parnell, also a [helicopter] pilot) both survived the crash.
To eliminate confusion, some use the word form. The word form actually contains the word “ceil” and “floor” to indicate the function and the number that is enclosed inside the parentheses. There is a rule that there should be no space between the function being used and the parentheses.
The idea of “bracket-like” characters might be more or less be identified with the General Category (gc) property values of Ps (Punctuation, open) and Pe (Punctuation, close). This category contains a few dozens of paired punctuation marks, mostly excluding quotation marks (categories Pi and Pf).
Parenthesis is of course Greek and means in fact "insertion". It has taken the meaning of the signs " ( " or " ) ". Parentheses is the regular plural. Usually, you use a pair of the signs showing an insertion, then "between parentheses" - or brackets ; however, "in parenthesis" means : as an afterthought.
A hole in the papyrus has obliterated βου π, but these letters are supplied by an ancient commentary on the poem. Second intermittent sources can be between ⸢ and ⸣. Quine corners are sometimes used instead of half brackets. The brackets stand for a function that maps a linguistic expression to its “denotation” or semantic value.