TASK DEFINITION: Given a negotiation between two participants, answer 'Yes' if both participants agree to the deal, otherwise answer 'No'.
PROBLEM: THEM: what would you like YOU: the ball and one hat THEM: fine.

SOLUTION: Yes

PROBLEM: THEM: ok what do you want YOU: books and hats and balls : x THEM: i need hats and one other of your choosing YOU: 1 ball then.

SOLUTION: Yes

PROBLEM: THEM: i would like both hats and the ball. YOU: i would like one of the hats THEM: if i give up a hat, i would need everything else. YOU: i'll just take both books.

SOLUTION:
Yes