use Test::More tests => 3;

my $x = "AB:APPLE:BOY:ZOO:ZOOM";

ok  isSubset('APPLE:ZOO' => $x);
ok !isSubset('BOY:GIRL' => $x);
ok  isSubset('AB:BOY:ZOOM' => $x);

sub isSubset
{
	my ($small, $big) = @_;
	$small =~ s{:}{:(?:[^:]+:)*}xg;
	
	return($big =~ /^(?:[^:]+:)*$small(?::[^:]+)*/);
}