Vaisesika Sūtra 1.2.2

न तु कार्याभावात् कारणाभावः ॥२॥

na tu kāryābhāvāt kāraṇābhāvaḥ ॥2॥

[न तु कार्य अभावात् कारण अभावः॥
na = not; tu = but; kārya = effect; abhāvāt = due to absence of; kāraṇa = cause; abhāvaḥ = is absent;॥]

But, in the absence of effect, there is no absence of the cause.