algebra.getUnion(a, b, aItems, bItems)

Unifies items from set A and setB into a single array of items.

algebra = new set.Algebra(
  set.props.rangeInclusive("start","end")
);
algebra.getUnion(
  {start: 1,end: 2},
  {start: 2,end: 4},
  [{id: 1},{id: 2}],
  [{id: 2},{id: 3},{id: 4}]);
  //-> [{id: 1},{id: 2},{id: 3},{id: 4}]