=IF(Thick_Back=0,IF(OR(G!Upper_Back_Construction<3,AND(G!Upper_Back_Construction<5,Left_Fin_End=1)),IF(G!FE_Type=3,IF(Left_Fin_End=1,Depth+FE_Scribe,Depth),Depth),G!Inside_Depth_Upper),Depth+IF(Left_Fin_End=1,FE_Scribe,0))