# Understanding of Gramian trick [closed]

I am now studying Gramian trick from this book : Recommendation systems handbook

However, I am having problem understanding its mechanism as well as its maths. I tried to look up the reference paper at [2] , but I got more confused.

Could anyone care to explain ?

• Rather than providing the screenshot of the relevant section of the book, please, copy and paste the part of the book that you don't understand and quote it by prepending it with the symbol >. You can use a tool like Mathpix Snipping Tool to quickly do it. Moreover, be more precise about what you understand and what you don't understand, and provide more context.
– nbro
May 14 at 10:58