Contour brep outputs different length list than input

[jonathan3 (Jonathan)]

I finally got the correct combination of search terms and found this discussion which was what I needed.

Tree problem: Add empty branches to list to match other list

Alright, I found a bug in one of my definitions and I need to match the data tree of the bottom list to the one on the top. Meaning that if there is a branch missing in the bottom list in comparison to the top list (like {1} and {3} in example below), it should create the same branch in the bottom list but without anything actually on that list. How do I add empty branches to a tree to match the other tree? [image] 190930 Tree matching.gh (8.3 KB) Thanks!