All the roots ending with the affixes san and others are called dhātu ,
This extends the sphere of Dhatu or roots already defined in sutra 1.3.1. These roots may be called derivative roots. They are separate independent roots, and have all the functions of a root, as taking tense-affixes &c. as shown in the above examples. Thus चिकीर्षा 'to wish to do', कारि 'to cause to do'; चेक्रिय 'to do repeatedly' are separate roots and not the same as कृ 'to do' and thus take शप् &c.,