Does not support lists within lists?

So I am making a list (lines) full of lists (each individual line, with x1, y1, x2, and y2) and after doing this, it draws the line.

When refreshscreen is called, 

clear the canvas. 

for each "line" in list "get global lines"

call canvas1.drawline

x1 = select list item : list = select list item : list = "get global lines"

                                                               : index = get "line"

                              : index = 1

y1 = select list item : list = select list item : list = "get global lines"

                                                               : index = get "line"

                              : index = 2

x2 = select list item : list = select list item : list = "get global lines"

                                                               : index = get "line"

                              : index = 3

y2 = select list item : list = select list item : list = "get global lines"

                                                               : index = get "line"

                              : index = 4

When I do this i get this error:

The operation select list item cannot accept the arguments: [((-10 -10 10 10))] [(-10 -10 10 10)]

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line is a sublist of global lines and not an index, therefore

x1 = select list item : list =  "get line"

                             : index = 1

etc.

see also

⦁ How to work with Lists by Saj

⦁ How to work with Lists and Lists of lists (pdf) by appinventor.org

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