An algebra teacher had just finished his lecture when he saw a female student... She had stayed behind after everyone else had left, furiously working away at proof exercises. The teacher walked up to her and said, ""Why are you working so hard?"" She looked up and responded: ""Harry Styles will marry me if and only if I finish top of my class."" The teacher looked bemused. ""How can you make such a claim?"" The student's face lit up. ""Well"", she said, ""let's say that I DO finish top of my class. Then I'll win lots of awards, and I'll spend the award money following Harry around on tour for six months after I graduate. That will get me enough knowledge to secure a management position at Harry's record company; I'll be able to meet him, and we'll fall in love and get married. So you see, if I finish top of my class, then Harry is sure to become my husband."" The teacher was impressed. ""That was good."" He said, ""But you only proved one direction.""