Abstract F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note. we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. https://www.diegojavierfares.com/amazing-offer-Wilwood-Compact-Brake-Master-Cylinder-special-find/