肇論新疏 3.153

3.153

亡不為無，故雖無而有；存不為有，故雖有而無。雖有而無，所謂非有；雖無而有，所謂非無。

Disappearance is not non-being, hence though non-being it is being; survival is not being, hence though being it is non-being. Though being it is non-being, this is what is called non-being; though non-being it is being, this is what is called non-non-being.