Wellformed

Wellformed is a term used across multiple disciplines to describe objects that conform to the rules of their underlying formal system. It is not a single organization or product, but a cross-disciplinary concept found in linguistics, logic, and computer science.

In linguistics, well-formed sentences adhere to the syntactic rules of a language. A sentence that violates grammar or allowable word order is considered ill-formed. The concept helps distinguish between strings that a grammar permits and those that do not. Well-formedness in language is a property of syntax rather than meaning.

In logic and formal languages, a well-formed formula (WFF) is a string of symbols that can be constructed according to the language’s formation rules. Only well-formed formulas are meaningful objects for evaluation or proof. The notion separates syntactic correctness from semantic truth.

In computing and data processing, well-formed data or documents conform to the syntax of their format or schema. Examples include well-formed XML, which requires proper nesting, a single root element, and valid attributes, and well-formed JSON, which uses correct punctuation and string quoting. Well-formedness is essential for reliable parsing and processing, but it does not guarantee semantic validity or correctness of the data.

Overall, wellformed emphasizes syntax-driven correctness within a formal system, serving as a prerequisite for further interpretation or computation.

See also: well-formed sentence, well-formed formula, XML well-formedness, data validation.