EXISTENTIALLY CLOSED STRUCTURES AND E-COMPANIONS  

作　　者：沈恩绍 

机构地区：[1]Beijing Normal University, Beijing 100875, PRC

出　　处：《Chinese Science Bulletin》1990年第6期441-444,共4页

摘　　要：The e-companions, f-companions and g-companions are three major classes of companions. Although maximal types can be applied to the depiction of existentially closed (abbr. e. c.) structures, they (even their modifications in complete types, normal types)

关 键 词：model theory existentially cloud STRUCTURES COMPANION operators. 

分 类 号：N[自然科学总论]