# Falsey.
?0 == False or die "Wrong state";   # Zero.
?0.0 == False or die "Wrong state"; # Zero (as float).
?"" == False or die "Wrong state";  # Empty string.
?() == False or die "Wrong state";  # Empty list.
?{} == False or die "Wrong state";  # Empty hash.
?Nil == False or die "Wrong state"; # Nil
my $v; ?$v == False or die "Wrong state"; # Undefined variable.

# Truthy: all non-falsey values.
?1 or die "Wrong state";
?1.0 or die "Wrong state";
?"Hello World" or die "Wrong state";
?(1, 2, 3) or die "Wrong state";
?{"one" => "eins", "two" => "zwei", "three" => "drei"} or die "Wrong state";
my $u = 99; ?$u or die "Wrong state";