However, in the auto-commentary to Abhidharmakośa-bhāṣya 倶舍論, Vasubandhu 世親 argues that this Sarvâstivādin 有部 doctrinal stance violates the doctrine of momentariness 刹那滅義 by presuming that all eight marks are present in a single dharma in a single moment. According to the standard Abhidharmic definition, a moment is the briefest duration of time that cannot be further analyzed into parts. For Vasubandhu, attempting to divide a moment into discrete parts is as futile as attempting to "carve up space"  分析虛空. In short, the Sarvâstivādin 有部 theory which maintains that eight marks are inherent in a single dharma in a single moment is said to contravene the definition of a moment as an indivisible duration of time. The Sarvâstivādin scholars defend the theory that eight characteristic marks pertain to each momentary dharma by positing an essence/function 體用 structure wherein a singular core entity can evince discrete (and even mutually incompatible) functions in a single moment (e.g., arising and cessation). The Sarvâstivādin theorists liken the arising, abiding, change, and ceasing of the eight conditioned marks in a single moment to a hen laying multiple eggs during the singular event of reproduction.