I’m looking at the RR diagram from https://duckdb.org/docs/sql/statements/select#full-syntax-diagram:

What would this look like in a grammar if we were to jus take the top-level items? My difficulty is in how the set-operation looks sort of removed from the others. Perhaps it could be the following?

select:
    [ common-table-expr ]
    { select-node | values-list | set-operation }

If so though, the following doesn’t make sense because it should be something like:

select set-operation select

What should this be?