Well, your title for the thread is how to compare if two rectangle redundant.

My understanding of the term is that "a rectangle is redundant if it is completely enclosed in another rectangle".

The condition that you have described is intersection, not redundancy.

I suggest you use a search engine (google or something) for terms "redundant rectangles" or "intersecting rectangles" and see if you get any information. These topics are typically covered in University courses with titles something like "Descriptive Geometry" or "Computational Geometry".

I really believe that doing your own web search is likely to be more productive for you than requesting help on a forum like this and waiting for a helpful response.

Good Luck,

Dave