Grasshopper tutorial practice

After three times trials, I suceed in the last time on sunday. This time, I wrote down all the key commands to keep myself be awared  of what goals the author was trying to obtain . Yet  more time is still needed to really think through the logic and the intention behind these commands.

The notes I took is as follows:
set curve
draw a polyline
view-plane radius-100
set integer:2
curve-perp frames
list item, set integer:1
vector-point-point polar
slider
cuver-analysis-end points
polyline
panel, first part of array; second part of array
flatten the input, true/false
sets-trees-flatten trees
list item, ctrl c, ctrl v
slider type: integers
list-shift list
W(rap)-set boolean-true
shift the whole list
polyline
joining them and shifting them to give them an order
ctrl c and ctrl v the whole logic, set it to another curve
deal with multiple segments
ctrl c and ctrl v, cut that into a new document
divide curve
troubleshoot the problem by using panel
(three deep in the array? four deep in the array?)