Why are the phase diagrams showing $G_s$ and $G_l$ situated so close on one end and then widens up at the other extremes? [closed]

With reference to the phase diagrams drawn in b and d why are the Gibbs phase lines coming closer from being so further apart?

• Those lines are just examples. As the temperature changes, the shape and relative position of the liquid and solid phase free energy curves will change. That is all. – Jon Custer Sep 11 '19 at 15:44