Mathematical Sciences Classification System
20Exx - Structure and classification of infinite or finite groups
- 
                            
                            20E05Free nonabelian groups
 - 
                            
                            20E06Free products, free products with amalgamation, Higman-Neumann-Neumann extensions, and generalizations
 - 
                            
                            20E07Subgroup theorems; subgroup growth
 - 
                            
                            20E08Groups acting on trees [See also 20F65]
 - 
                            
                            20E10Quasivarieties and varieties of groups
 - 
                            
                            20E15Chains and lattices of subgroups, subnormal subgroups [See also 20F22]
 - 
                            
                            20E18Limits, profinite groups
 - 
                            
                            20E22Extensions, wreath products, and other compositions [See also 20J05]
 - 
                            20E25Local properties
 - 
                            20E26Residual properties and generalizations; residually finite groups
 - 
                            
                            20E28Maximal subgroups
 - 
                            
                            20E32Simple groups [See also 20D05]
 - 
                            
                            20E34General structure theorems
 - 
                            
                            20E36Automorphisms of infinite groups [For automorphisms of finite groups, see 20D45]
 - 
                            
                            20E42Groups with a $BN$-pair; buildings [See also 51E24]
 - 
                            
                            20E45Conjugacy classes
 - 
                            20E99None of the above, but in this section