Composition, Semantics and Communicative Purpose

semantic), written form, abstract model, delimitation into the title and

SPUs, cohesion, and communicative intention [Galperin];
a continual succession of sentences centering on a common information purpose and characterized by semantic (topical) unity and semantic-syntactic cohesion [Bloch];
a social phenomenon, a basic unit of speech characterized by the topical, structural and communicative unity [Moskalskaya].

a linguistic sign

resume, the main episode, conclusion, etc.) [Van Dijk].

research

from propositions of the original text according to certain rules

(macro-rules) -- integration, deletion, construction [Van Dijk].
E.g., John went to Paris yesterday. He took a cab to the station. He bought tickets. He took the train to Paris. → John went to Paris yesterday (macro-proposition).

of the component sentences:
monologue sequence dialogue sequence (one direction) (two directions) cumuleme occurseme (topical element) (exchange-topical element)
The

communicative unity is exposed in the communicative succession b/w text constituents (rheme → theme): E.g., She saw a boy. The boy was young.