UNION, INTERSECT and EXCEPT

These operators default to DISTINCT. Add ALL when duplicate occurrences matter.

FOR n IN [1, 1, 2] RETURN n
UNION ALL
RETURN 2 AS n;

For a complete row that appears L times on the left and R times on the right:

Operator	Occurrences
UNION ALL	L + R
INTERSECT ALL	min(L, R)
EXCEPT ALL	max(L − R, 0)

Null fields compare equal for matching result rows. Branch schemas must have the same column names, count and order. Types must match or permit supported null/numeric widening; differently named columns are not automatically aligned. Integer and float lists widen the same way, including nested lists. An empty list is accepted beside a typed list. A string or boolean list cannot be combined with a number list.

Each branch has an independent binding scope. A branch-local graph selection does not modify another branch or the session. Only one conjunction kind is accepted at a composite level; use nested query braces to combine levels. Composite writes are rejected before branch execution.

ORDER BY, OFFSET, and LIMIT written on the last branch apply to the combined rows and see those result columns. Put a branch-local page inside braces when it should not page the composite.