New [Set] menu

[compsystems]

I notice that in the LIST menu, it has three set commands, but the list type is not always equal to a set

test

index:=1:; E_ := [ "H", "E", "L", "L", "O" ]:;
find( "L", E_ ) [enter]
[3,4] // "L" is in two positions
index(E_,"L") [enter]
3

F_ := set[ "H", "E", "L", "L", "O" ] [enter] set[ "H", "E", "L", "O" ]
find( "L", F_ ) [enter]
[3] // "L" is in one positions
index(F_,"L") [enter]
3

E_ == F_ [enter] false

also diference cmd does not work on a set
DIFFERENCE(set["b","a","c","a"],set["a","d"]) [enter]
{"b","c","d"}

set[ "b", "a", "c", "a" ] minus set[ "a", "d" ] [↵] set["b","c"]