# Function setDifference Create the difference of two (multi)sets: every element of set1, that is not the element of set2. Multi-dimension arrays will be converted to single-dimension arrays before the operation. ## Syntax ```js math.setDifference(set1, set2) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `a1` | Array | Matrix | A (multi)set `a2` | Array | Matrix | A (multi)set ### Returns Type | Description ---- | ----------- Array | Matrix | The difference of two (multi)sets ### Throws Type | Description ---- | ----------- ## Examples ```js math.setDifference([1, 2, 3, 4], [3, 4, 5, 6]) // returns [1, 2] math.setDifference([[1, 2], [3, 4]], [[3, 4], [5, 6]]) // returns [1, 2] ``` ## See also [setUnion](setUnion.md), [setIntersect](setIntersect.md), [setSymDifference](setSymDifference.md)