Definition: Given a negotiation between two participants, answer 'Yes' if both participants agree to the deal, otherwise answer 'No'.
Input: THEM: i'd like the two balls and two hats... are books useful to you? YOU: how about i get the 2 books and either 1 ball or 1 hat? THEM: i suppose that's right down the the middle for us. deal, pick which you want and let me know. YOU: okay, i'll take 2 books and 1 hat.
Output:
Yes