Proof of `Structural Parameters of the Conflict Graph` (4th statement)
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
Compose the two reductions of Lemmas 14 and 15. The image of the first is the code of an instance of treewidth at most four whose parameters are at most its number of days, or the rejected word; the second raises the treewidth by at most two.