We host a combinatorial seminar. A certain David is giving a talk on 1-factorisations of graphs. He makes the absurd claim that "It is hard to decide if a graph has a 1-factorisation."

"Not cliques," I take him up on it.

"No, not cliques." he agrees.

"Ha!" I yell. And everyone politely claps. He continues talking.

A few minutes later I pipe up again, "Except odd cliques."

"Sorry?" he says.

"It isn't easy to tell if odd cliques have factorisations."

"Oh. That again. Actually it is, they don't."

"So you can't tell if they do." I push my point.

"You can. They don't."

People are getting nervous. "So if they do, you can't tell it, or you would be wrong, right?"

"Right." he says. "But that is not what anyone is talking about. We are talking about math here, and you are babbling vacuous nonsense."

"So you agree, then." I ask.

"Sure, if we can move on."

"Ha!" I yell. Everyone claps.

I think that everyone would agree that I won the seminar. I'm 5-2-1 over the last eight. Not a bad record. I hope they consider this when my contract comes up for review.