So according to our sequential model, this is the only time that our structure will exist in the art state. And we know that is not true. We know in nature. What we see experimentally is when three of those heme groups are filled with oxygen, the structure of the hemoglobin will exist predominantly in the r state, which is exactly what we see according to our concerted model. Based on the concerted model, when three of these heme groups are filled with oxygen, our r state will predominate. So this arrow will be longer than this arrow, which is basically the correct description of what actually happens in nature.