at is the substitute of jha after a reduplicated verbal aṅga (stem).,
As द꣡दति, ददतु, दधति, दधतु; जक्षति, जक्षतुः जाग्रति, जाग्रतु ॥ This अत् is replaced by जुस्, as अददुः, अदधुः ॥ Here also the accent will be on the first syllable of the substitute. Thus अ꣡ति, अ꣡त, अ꣡ते, अ꣡तु, अ꣡ताम् in the subsequent sutras. The accent of the reduplicates, however, is governed by (VI. I. 189), (अभ्यस्तानामादिः) ॥,