Symmetric difference

my \A = set <John Serena Bob Mary Serena>;
my \B = set <Jim Mary John Jim Bob>;

say  A ∖ B; # Set subtraction
say  B ∖ A; # Set subtraction
say  A ⊖ B; # Symmetric difference

Output:

set(Serena)
set(Jim)
set(Jim, Serena)