This substitution does not take place when a sound-imitation word is doubled, here, however, for the final t + i , the single substitute is optionally i (the second vowel).,
Thus पटत्पटदिति or पटत्पटेति करोति (पटत्पटत् + इति = पटत्पट + इ + ति = पटत्पटेति) ॥ The word is doubled by 8.1.4. The para-rupa substitution will take place when the whole word so reduplicated denotes a sound imitation, thus पटत्पटिति करोति ॥ Here we apply the preceding sutra. The amredita is the name of the second member of the doubled word 8.1.2.,