يُعْرَفُ بِهِ إِيرَادُ الْمَعْنَى الْوَاحِدِ
Through it one learns how to express one and the same intended meaning.
بِطُرُقٍ وَتَرَاكِيبَ مُخْتَلِفَةٍ فِي وُضُوحِ الدَّلَالَةِ عَلَيْهِ
By methods and constructions that differ in how clearly they indicate that meaning.
Two elements determine the discipline's focus: unity of the intended meaning and variation in the clarity of its expression. Producing several unrelated sentences is not the point; the expressions must converge on the intended meaning while differing in how they communicate it.