Maria Cantu had a teaching contract with the San Benito Consolidated Independent School District. She hand-delivered to her supervisor a written offer to resign. Three days later, the superintendent of schools mailed her a letter accepting the offer of resignation. Ms. Cantu then changed her mind and the next day hand-delivered a letter withdrawing her resignation. The superintendent refused to recognize the attempted rescission of the resignation. Ms. Cantu appealed to the state district court. It decided against her, and she again appealed. Is there a contract or not? Explain your answer. [Cantu v Central Education Agency, 884 S.W.2d 565 (Tex. App. 1994)]