San Francisco (CNN Business) People are great at arguing. But a project from IBM shows that computers are getting quite good at it, too.

On Monday, Harish Natarajan , a grand finalist in 2016's World Debating Championships, faced off against IBM's Project Debater — a computer touted by the company as the first artificial-intelligence system built to meaningfully debate humans. Natarajan won, but the computer demonstrated the increasingly complex arguments that AI is starting to make.

Project Debater, which has been in the works since 2012, is designed to come up with coherent, convincing speeches of its own, while taking in the arguments of a human opponent and creating its own rebuttal. It even formulates its own closing argument. To generate its arguments and rebuttals, Project Debater uses newspaper and magazine articles from its own database, and also takes in the nuances of the human opponent's arguments. It is not connected to the internet and cannot crib arguments from sites like Wikipedia.

Monday's debate, which was organized by nonprofit debate-hosting company Intelligence Squared US, was held in front of an audience in San Francisco's Yerba Buena Center for the Arts. The topic of the debate — whether or not preschool should be subsidized — wasn't revealed to the AI system or Natarajan until 15 minutes before they took to the stage. Project Debater argued in favor of subsidized preschool.

It followed traditional debate style. Each side gave a 4-minute opening speech, then they each came up with a 4-minute rebuttal to the other party. At the end, they gave a 2-minute closing argument. The audience was asked to vote for one side or the other at the start of the debate, and again at the end.

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