The participles dāśvām , sāhvān , and mīḍhvān are irregularly formed without reduplication.,
The word दाश्वान् is from the root दाशृ 'to give' with the affix क्वसु 3.2.107, here the reduplication and the augment इट् are prohibited irregularly. As दाश्वांसो दाशुषः सुतम् (Rig I. 3. 7). The word साह्वान् is derived from the root सह् 'to endure', by adding the affix क्वसु 3.2.107, the irregularity being in lengthening the penultimate, not allowing the augment इट् and the reduplication. Thus साह्वान् बलाहकः ॥ So also मीढ्वान् comes from मिढ् 'to sprinkle' with the affix क्वसु 3.2.107 the irregularity consisting in non-reduplication, non-application of इट्, the lenghthening of the penultimate vowel, and the change of ह into ड ॥ As मीड्वस्तोकाय तनयाय मृडय ॥ It is not necessary that these words should be in the singular always, in their plural forms also they do not reduplicate.
Vart:- Reduplication takes place when कृञ् &c, are followed by the affix क ॥ Thus क्रियते अनेन = कृ + क = चक्रम्, क्लिद् + क = चिक्लिदम् ॥ The affix क comes after कृञ् and क्लिद् with the force of the affix घञ् ॥
Vart:- The roots चर्, चल्, पत्, and वद् take reduplication when followed by the affix अच् 3.1.134 and the reduplicate (abhyasa) takes the augment आक् ॥ The final consonants of the Abhyasa (reduplicate) are not elided in these verbs, in order to give scope to the augment, for if the final consonants be elided by 7.4.60, then the addition of the augment becomes unnecessary; as there is no difference between the augment and the adesa (shortening of the vowel) taught in 7.4.59. Thus चराचरः, चलाचल, पतापतः, वदावदः ॥
Vart:- The above vartika is optional, so we have the forms चरः पुरुषः, चलो रथः, वदो मनुष्यः &c.
Vart:- The root हन् is reduplicated before the affix अच्, and the augment आक् comes after the Abhyasa, and घ is the substitute of ह of the Abhyasa. Thus हन् + अच् = घन् + आक् + हन् + अच् = घनाघनः (The second ह is changed into घ by 7.3.55), as in the phrase घनाघनः क्षोभनश्चर्षणीनाम् ॥
Vart:- The causative root पाटि is reduplicated before the affix अच्, there is elision of णि (sign of the causative), and उक् is the augment of the Abhyasa, and it is lengthened. Thus पाटि + च् = पाटूपटः ॥,