The Structural and Functional Nature of Text: Language, Speech, and the Invariant–variant Relationship

The article examines the concept of the texteme as the invariant structural unit underlying different text realizations. Based on the principle of isomorphism, it distinguishes between the text as an abstract linguistic model and the text as its realization in actual communication. It argues that lexical and grammatical synonymy, together with grammatical variation, produce multiple text variants while preserving the semantic and communicative identity of the texteme. The study also classifies textemes according to their semantic-logical organization and explains how they generate different variants within macrotexts. Overall, it concludes that the invariant–variant approach provides an effective framework for analyzing the relationship between stable textual structures and their context-dependent realizations.