Source
Clarifications: Axioms for Learning from Pairwise Comparisons
Lemma 2.3 distinct
alternatives
Positive directed counts for every pair → every distinct
pair. Diagonal counts are zero in the paper’s
pairwise-comparison model, so the literal all-pairs premise cannot
hold.
Counterexample
proofs for Theorems 5.3 and 6.3
Continuity of the maximizer under small perturbations → a
compact likelihood-gap argument. A uniform score bound
restricts the search to a compact set; a strict base-likelihood gap
separates the bad-order set. An explicit positive rational perturbation
is chosen whose bounded likelihood contribution cannot close that gap.
The construction retains a strict score reversal under the source
assumptions.