@DavidKButlerUoA @Whitehughes I had a strong sense while going through my solution that I was really just repeating a similar example I'd seen before. I tried to mention the points where I'd made a decision or needed to check something, but I definitely skipped explaining some bits
@DavidKButlerUoA @Whitehughes I suppose mathematical fluency is having that stock of stuff you use without really thinking about it