After a word in the Instrumental -3rd case in construction an affix is used in the sense 'discovered by him'.,
Knowledge acquired by oneself without being taught is called उपज्ञातं, i.e. an intuition or self taught knowledge. Thus पाणिनिनोपज्ञातं = पाणिनीयम् अकालकं व्याकरणं 'the law of Grammar discovered by Panini'. So also काशकृत्स्नम् गुरुलाघवम्, आपिशलम् दुष्करणम् ॥ Compare 2.4.21. The Panini's Grammar is called अकालकं as it does not define काल or tenses; गुरुलाघव is the name of the sciences of wealth (यत्रोपायाणां गौरवं लाघवं चिन्त्यते) ॥ The word Duskarana is the name of a Grammar, so-called because of the technical term दुषू occurring in it. Some say it means कामशास्त्रः ॥,