So as long as this quantity is greater than this quantity, this will always be a positive value. This will always be greater than zero. Now, what we want to attempt to do in this lecture is to derive an equation by beginning with this equation and by using the definition of entropy, we want to derive an equation known as the Gibbs free energy. And this equation basically gives us the conditions under which a reaction is spontaneous and under which the reaction is not spontaneous. So let's call this equation number one, and let's recall what the definition of entropy is for constant temperature. Now, the reason we're going to assume constant temperature is because all the different types of biological reactions that take place in nature usually take place under constant temperature conditions.