Check if an element is within a sequence

Question

how to check if an element is contained within a sequence? I expected some Seq.contains, but i could not find it. Thanks

EDIT: Or, for an easier tas

Answer 1

Set is your friend here:

let a = set [0;1;2;3]
let b = set [2;3;4;5]
let c = a - b
let d = b - a
let e = Set.intersect a b
let f = a + b
> 
val c : Set = seq [0; 1]
val d : Set = seq [4; 5]
val e : Set = seq [2; 3]
val f : Set = seq [0; 1; 2; 3; ...]

Danny