why loop of i only has variable j

[tiemuhua]

from line 1496 to line 1519, this two for loops has variable i, but in the loop body, there is no i, only j, why?
1496行到1519行这两个for循环是关于i的，但是循环体里面为什么只有j没有i？

[ZhepeiWang]

These code blocks are the two-loop recursions of limited memory update (https://en.wikipedia.org/wiki/Limited-memory_BFGS). The variable "i" is just used for counting the number of loops. It is the variable "j" that sequentially accesses the memorized "s" and "y".

[ZhepeiWang]

Appreciate your review of this repo. I close it here but any further issue is welcomed.