I have 2 lists of curves which have the same structure. How can I get the curves in list 2 that do not intersect with curves in list 1?

You mean geometric intersection or set intersection ?

For the second option, I think that you can use List.SetDifference

I mean geometric intersection. The curves in each list do not have the same order but I want to find the curves that do not intersect with the other list.

I think what you have started to do is great. Maybe add an List.AllFalse before the filtering to check if each curve has at least one intersection with the other list.

Here is the simplify graph.

Test.dyn (14.6 KB)

and the Revit file https://www.dropbox.com/s/ky1550dse5pcb0n/Test.rvt?dl=0

I would add a List.Contains node, searching for ‘true’ with lacing longest or level set to 2. This will return a single ‘true’ value for any line which intersected any of the other lines, or false if there was no intersection. You can then use a List.FilterByBoolMask and get the excluded set.

Or use “List.AnyTrue”

Also would work.

Thank you all!