Starting from 'That is to say, beside Indo-European and Indo-Hittite, there must have existed an Indo-Slurvian.', does it naturally lead to the conclusion 'There must definitely not exist an Indo-Slurvian.'
That is to say, beside Indo-European and Indo-Hittite, there must have existed an Indo-Slurvian.###There must definitely not exist an Indo-Slurvian.