Difference of two sets or of two lists

The minus operator is an infixed operator that finds the set difference of the elements of two sets or lists; the result will always be a set.

set[1,2,3,4] minus set[5,6,3,4]

or:

[1,2,3,4] minus [5,6,3,4]

⟦ 1,2 ⟧