तयोर्मानुषोपेतो ज्येष्ठांशादर्धं लभेत ॥ कZ_०३.६.१२ ॥
tayormānuṣopeto jyeṣṭhāṃśādardhaṃ labheta
Of those two, the one established by human agency/acknowledgment (mānuṣopeta) shall receive half of the eldest son’s share.
It creates an administrative reference point for proportional allotment, simplifying calculations and reducing contestation.