1. A text analysis system comprising: a natural language input unit for enabling a user to input a free text in a natural language; a natural language processing unit for processing at least a portion of the free text while it is being inputted, to obtain an explicit representation semantics entailed by the free text; an explicit information input unit for enabling the user to input explicit information relating to the explicit representation of semantics; and a user interface for providing a user with simultaneous access to both the natural language input unit and the explicit information input unit.