[EM] Oops (re resistant set extension)

[Kristofer Munsterhjelm]

I missed an obvious counterexample for the first preference-based extension.

34: A>B>C
33: B>C>A
33: C>A>B

Now (A,B) ~> C since 34 + 33 > 50,
{B, C} ~> A since 33 + 33 > 50
and {C, A} ~> B since 33 + 34 > 50

hence a cycle.

So that relation (with that threshold) is unsuitable. If the first 
preference extension is to be salvaged, the threshold can't be 1/(k-|S|+1).

-km