पूर्वम् अर्धम्
कर्मधारय — the front half
पूर्वार्धेन लम्बते इति
तत्पुरुष (instrumental) — one who leans down by that front half
तत्पुरुष — it agrees with त्वम्. leaning down by its forequarters — the picture is an elephant with its front half tipped toward the water and its hind half still up in the air. पूर्वार्धम् is a compound Pāṇini writes a rule for: 2.2.1 पूर्वापराधरोत्तरमेकदेशिनैकाधिकरणे puts पूर्व, अपर, अधर and उत्तर together with the word for the whole they are a part of. The last member is लम्बिन्, an agent noun in णिनि by 3.2.78 सुप्यजातौ णिनिस्ताच्छील्ये, which makes such a noun after a case-form standing in front of it — the same suffix that made भावि at 1.43 and प्रापि at 1.46. **Mallinātha reads पश्चार्धलम्बी here, not पूर्वार्धलम्बी**, and spends four clauses on it: पश्चादर्धं पश्चार्धम्, glossed पश्चिमार्धम्, 'the hind half', which he declares sound by पृषोदरादित्वात् — Pāṇini 6.3.109 पृषोदरादीनि यथोपदिष्टम्, the rule that lets a word whose letters have been dropped or altered outside any stated rule stand as correct because the learned use it. He needs that licence because पश्चात् is an indeclinable and is not one of the four words 2.2.1 names, so पश्चार्ध cannot be made the regular way and पूर्वार्ध can. Both readings draw the same elephant: his gloss of his own reading is पश्चार्धभागेन व्योम्नि स्थित्वा पूर्वार्धेन जलोन्मुखः, 'standing in the sky by its hind part, its front part turned toward the water'
uncheckedMallinātha, Sañjīvinī, on the reading पश्चार्धलम्बी; Pāṇini 2.2.1, 3.2.78 and 6.3.109 by way of skt-mcp; the analysis of पूर्वार्धलम्बी, which is what this text prints, is the reader's“paścādardhaṃ paścārdham | paścimārdhamityarthaḥ || pṛṣodarāditvātsādhuḥ || tena lambata iti paścārdhalambī san paścārdhabhāgena vyomni sthitvā | pūrvārdhena jalonmukha ityarthaḥ”