“…The for loop between Line 4 to 6 reduces the ith basis vector and creates non-zero entries r k,i , k = i + 1, ..., j. The first part of the process Triangulate R eliminates the non-zero entries from r j,i to r i+1,i by the plane rotations [19,20]. The elimination process will create another sequence of non-zero elements r k+1,k , k = i + 1, ..., j − 1 on the subdiagonal.…”