r0 := UnboundTable: t
  a int64

r1 := Selection[r0]
  predicates:
    r0.a < 42
    r0.a >= 42

r2 := Selection[r1]
  selections:
    r1
    x: r1.a + 42

r3 := Aggregation[r2]
  metrics:
    y: Sum(r2.a)
  by:
    x: r2.x

Limit[r3, n=10]