From semantic representations to surface phonologic representations, seven different levels of linguistic representation are supposed for each set of synonymous utterances.
both of them are based on directed labelled graph structures, and some research has been done towards using them to represent dependency structures and knowledge of the ECD (OWL in (Lefrançois and Gandon, 2011;boguslavsky, 2011), CGs at the conceptual level in (bohnet and Wanner, 2010)).