sub as_bool { $_[0] ? "true" : "false" }

my @greetings = qw( Hi Bye );
say as_bool("Hi" ~~ @greetings);     # true
say as_bool("Hiya" ~~ @greetings);   # false

##</code><code>##

push @greetings, 0, 1;
say as_bool(0 ~~ @greetings);       # true
say as_bool(1 ~~ @greetings);       # true
say as_bool(2 ~~ @greetings);       # false
say as_bool("Hiya" ~~ @greetings);  # true ?!?!