> In maths, you know when you've got an exercise right, and so you don't need the answer written out for you. No, I might think I have the correct answer but I

> In maths, you know when you've got an exercise right, and so you don't need the answer written out for you. No, I might think I have the correct answer but I cannot know until I have seen the correct answer. I can justify any false answer that's not obviously false for myself which is why I need to compare.