amount = 1 Move the cursor up amount lines.
If amount is greater than the maximum move distance then it is internally adjusted to the maximum. If amount is 0, adjust it to 1.
This unsets the pending wrap state without wrapping.
If the current scroll region is set and the cursor is on or below top-most line of it then the cursor may move up only until it reaches the top-most line of current scroll region.
If the current scroll region is not set or the cursor is above top-most line of current scroll region it may move up until the top of the screen (excluding scroll-back buffer).
amount = 0, is not adjusted to 1.🛆 If cursor origin is active the cursor is constrained to the current scroll region. Otherwise the scroll region is ignored.