The augment suṭ is placed before ka , when the verb kṛ comes after upa , and the sense is that of 'to take pains for something, to prepare, and to supply and ellipses in a discourse'.,
To take pains in imparting a new quality to a thing in order to increase its value, or to keep it safe from deterioration is called प्रतियत्नः ॥ That which is prepared or altered is called वैकृतं ॥ The word वैकृतं is the same as विकृतं, the affix अण् being added without changing the sense, by considering it to belong to प्रज्ञादि class 5.4.38. To supply by distinct statement the sense of a sentence which is alluded to, is called the अध्याहार of a sentence. Thus in the sense of 'taking pains' we have एधोदकस्योपस्कुरुते (See 1.3.32); काण्डगुणस्योपस्कुरुते ॥ In the sense of 'altering by preparing' we have: उपस्कृतं भुङ्क्ते, उपस्कृतं गच्छति ॥ In the sense of 'supplying a thesis' we have उपस्कृतं जल्पति, उपस्कृतमधीते ॥ When not having any one of the above five senses (VI. I. 137) - 6.1.139 we have उपकरोति ॥,