By letter, Martine offers to landscape Harry's yard for $500. Harry thinks that is too much, and on Monday he mails a rejection. However, on Tuesday Harry realizes Martine was giving him a good deal, so he mails an acceptance. Martine however changed her mind about the job on Wednesday, and mailed a revocation, which Harry receives on Thursday. On Friday, Martine receives Harry's acceptance. On Saturday, she receives his rejection. Which best describes the situation?