sub IsMember {
my %Set = ( 'age' => 1, 'old' => 1, 'years' => 1);
return $Set{$_[0]};
}

##</code><code>##

{
my %Set = ( 'age' => 1, 'old' => 1, 'years' => 1);
sub IsMember {
return $Set{$_[0]};
    }
}

##</code><code>##

sub IsMember {
return $_[0] =~ m/age|old|years/;
}