Gorgias and Plato's Sophist

My aim is to investigate the link between Plato's Sophist and Gorgias's treatise On What Is Not. This relationship is worth examining because Gorgias's treatise constitutes an essential, but insufficiently studied stage in the intellectual journey leading from Parmenides to the Sophist. My claims are that 1) Plato's agenda in the Sophist perfectly meets the challenges Gorgias raises in the first thesis of his treatise, that 2) this becomes clear once we focus on Gorgias's and Plato's respective use of the verb 'to be' and, finally, that 3) Plato is able to overcome Parmenides's impasse precisely because he deals with Gorgias's treatise.