Just uploaded the revised version of "The Heart Sutra" (Free translation) as follows: http://www.slideshare.net/compassion5151/the-heart-sutra-free-translation
I made this revised version because I mixed up "the conventional truth" and "the ultimate truth" in old versions. The Four Noble Truths is in the realm of the conventional truth and the Heart Sutra is in the realm of the ultimate truth. And it's essential for us to understand the ultimate truth for attaining enlightenment. The ultimate truth is "the wisdom of interdependence (emptiness)" which means "change (impermanence)", or "empty of separate existence or self (no self)". In other words, "change is the foundation of existence" (everything can survive because it's changing). Therefore, it's vital for us to be "non-separate existence or self" (interdependent existence or self).