Parentesis

Parentesis are punctuation marks used to enclose material that is supplementary to the main text or to indicate grouping in mathematical expressions and logical notation. The standard form consists of an opening and a closing symbol, with the most common pair being round parentheses: ( and ). Other forms include square brackets [ ], curly braces { }, and angle brackets ⟨ ⟩, each serving different disciplinary conventions or typographic needs.

Origin and naming: the term derives from the Greek paréntēsis, meaning “placing beside.” In many languages the same concept is referred to as paréntesis or similar, while in English the term is parentheses (singular parenthesis).

Usage in writing: parentheses enclose information that is tangential or clarifying, such as aside remarks, abbreviations, or examples. They may also indicate numerical references or citations within a text. As a rule of readability, excessive use of parentheses is discouraged, and writers often substitute other devices (such as dashes) for long asides.

Mathematics, logic, and computing: in mathematics, parentheses group terms and indicate the order of operations, as in a(b + c) or (x − y)2. They define function arguments, coordinate expressions, or intervals in notation such as [0, 1] or (0, ∞). In computing and programming, parentheses appear in function calls, control structures, and expressions.

Typography and spacing: typographic conventions vary by language, but generally there is no space immediately inside the opening parenthesis or immediately before the closing one. In multilingual texts, consistency in style and punctuation is important for clarity.