Kifejezéscsoport

Kifejezéscsoport is a term used in Hungarian to denote a group of expressions forming a unit within a formal theory. Its exact meaning depends on the context, but it generally refers to a collection of expressions together with a specified operation that combines them and governs their algebraic or syntactic behavior.

In mathematics and formal languages, a kifejezéscsoport typically means a set whose elements are expressions built from a fixed alphabet, equipped with a binary operation that combines expressions. Depending on the theoretical framework, the structure may satisfy the axioms of a group (closure, associativity, identity, inverses) or only weaker axioms such as those of a monoid or semigroup. The emphasis is on how expressions can be manipulated, reduced, or related through a defined rule system, often modulo a set of equations or relations.

In linguistic or grammatical contexts, the term can refer to a syntactic unit that consists of several expressions functioning together as a larger unit, such as a phrase group. The exact composition and terminology are language-dependent, with Hungarian grammar using terms like noun phrases or verb phrases to describe similar constructions.

Usage notes indicate that kifejezéscsoport is not a universally standardized term across all subfields. When encountered, it is important to consult the specific definition and the accompanying operation or rules in that particular theory to understand what constitutes the group, its elements, and its purpose.

Related topics include group theory, formal languages, term algebras, and syntax/phrase structure.