 \\ \to & {\curly Ext}^0(F,F) & \to & {\curly Ext}^0(I^\bullet,I^\bullet) & \to & {\curly Ext}^0(I^\bullet,{\mathcal O}_{Y \times E}) \\ \to & {\curly Ext}^0(F,F) & \to & {\curly Ext}^0(I^\bullet,I^\bullet) & \to & 