Can’t boolean union two SubD forms

Rhino SubD
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1

I want to merge the two subD together but Rhino show “!” in some of the subD surface. Are there any ways that I can merge two subD together , Thank You
cat.3dm (4.2 MB)

2

Since neither of the two SuBD objects is closed, you can first run the Fill command to quickly close them, and then run BooleanUnion. The demo is as follows,

3

Thank You I am able to Union the subD together.