Let G and F be abelian groups.Recall that Pext(G,F) is the subgroup ofthose extensions0 → F → E → G → 0so that each finitely generated subgroup of G lifts最后的“lifts”是怎样定义的?这是原版论文里的一段话（论文是英

Let G and F be abelian groups.Recall that Pext(G,F) is the subgroup ofthose extensions0 → F → E → G → 0so that each finitely generated subgroup of G lifts最后的“lifts”是怎样定义的?这是原版论文里的一段话（论文是英
Let G and F be abelian groups.Recall that Pext(G,F) is the subgroup of
those extensions0 → F → E → G → 0
so that each finitely generated subgroup of G lifts
最后的“lifts”是怎样定义的?
这是原版论文里的一段话（论文是英文的）我也不知道应该把那个“lifts”翻译成中文中一个什么词
还有我是诚心问的 还特别注明了向数学达人请教 请那位说“秀啥？”的人自重！

Let G and F be abelian groups.Recall that Pext(G,F) is the subgroup ofthose extensions0 → F → E → G → 0so that each finitely generated subgroup of G lifts最后的“lifts”是怎样定义的?这是原版论文里的一段话（论文是英
设G和F是阿贝尔群体.记得,Pext的（ g ,f ）是分组
这些extensions0 → → F → é位G → 0
使每个有限生成的子群的G升降机