require "map"
local fmt = require "fmt"

local a = set.of("John", "Bob", "Mary", "Serena")
local b = set.of("Jim", "Mary", "John", "Bob")
fmt.print("A     = %s", a)
fmt.print("B     = %s", b)
fmt.print("A - B = %s", a:except(b))
fmt.print("B - A = %s", b:except(a))
fmt.print("A △ B = %s", a:symdiff(b))