Now let's take a look at Gibbs free energy, equation five. So, on the right side of this equation, this term is the same as this term here, and this term is the same as this term here. So, according to equation five, and according to this inequality, this quantity must be less than this quantity. And if this quantity is greater than this quantity, if we take their difference, we get unnegative value. So what that means is a biological reaction that takes place inside our body or inside our cells increases the entropy of the universe only if the gifts free energy is actually a negative value. And that means when the gifts free energy is a negative value, our reaction under that particular condition, at that particular temperature, is a spontaneous reaction.