anena paridṛśyamānena paśunā sadṛśo gaur ityevamākāraṃ parokṣagoviṣayaṃ yajjñānamupajāyate tadupamānaṃ pramāṇam
The cognition that arises in the form "a cow is similar to this visible animal" concerning an unseen cow - that is the means of knowledge called analogy