Short a is substituted for the vowel of the reduplicate in the reduplicated Aorist of the Causative of the roots 1. smṛ 2. dṝ 3. tvara 4. pratha 5. mrada 6. stṝ and 7. spaś,
Thus असस्मरत्, अददरत्, अतत्वरत्, अपप्रथत्, अमम्रदत्, अपस्पशत् ॥ This debars the इ which would have come under 7.4.93. The short अ indicates that it is not to be lengthened by 7.4.94, as अददरत् ॥,