It is proved, under MA+CH, that the inverse image of a normal space under a two to one closed mapping is not necessarily normal and that each topological space with a strictly positive regular finite Borel measure has calibre 1.是什么意思_It is proved, under MA+CH, that the inverse image of a normal space under a two to one closed mapping is not necessarily normal and that each topological space with a strictly positive regular finite Borel measure has calibre 1.在线翻译_英语_读音_用法_例句