r0 := UnboundTable: right
  time2  int32
  value2 float64
  b      string

r1 := UnboundTable: left
  time1 int32
  value float64
  a     string

r2 := InnerJoin[r1, r0] r1.a == r0.b

r3 := InnerJoin[r2, r0] r1.value == r0.value2

Selection[r3]
  selections:
    time1:        r2.time1
    value:        r2.value
    a:            r2.a
    time2:        r2.time2
    value2:       r2.value2
    b:            r2.b
    time2_right:  r0.time2
    value2_right: r0.value2
    b_right:      r0.b