> I have written code to traverse matrices in which I use indices `I` and `J` to iterate over submatrices and indices `i` and `j` to iterate over individual val

> I have written code to traverse matrices in which I use indices `I` and `J` to iterate over submatrices and indices `i` and `j` to iterate over individual values in a submatrix. Please notice that the first letter in Nim is case-sensitive, so `I` != `i`, and you can continue use your conventions. And before some new comment starts bashing that, I think this is a must so you can differentiate your types, written in PascalCase, from your variables, written in camelCase.