There are two parties - A and B. They are normal friends. A wants to buy B's house at a specific price, however they don't sign the formal contract. Instead of it, they write "subject to contract" and other details such as the location of the house, date, and price in a piece of paper. Few days later, B decided not to sell his house to A. Assume A didn't pay anything to B for his house in advance. The question is: Is there a contract between A and B?