Proof of `Deleting high-degree vertices in an independent blow-up` (1st statement)
groundedproofs/Lax263307Proofs/BlowUpDeletion.lean · lax-263307
What this proof establishes
Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.
Description
Every nonisolated survivor belongs to a fibre of size at most : a surviving neighbor has degree at least that fibre size. Embed these survivors into the uniform -fold blow-up, pull back its lifted decomposition, insert the isolated survivors in singleton bags, and add the removed vertices to every bag.
Attribution
Bonnet–Chang, proof of Lemma 16.