问题9：同态映射是否也保持了两个系统 的结构“相似性”？ Proposition 11.1 Let:GG2 be a homomorphism of groups.Then 1.If e is the identity of G,then (e)is the identity of G2; 2.For any element g∈Gi,p(g-1）=[p(gl-1; 3.If H is a subgroup of G1,then (H1)is a subgroup of G2; 4.If H2 is a subgroup of G2,then (H)=g EG:(g)E H2}is a subgroup of G1.Furthermore,if H2 is normal in G2,then (H2)is normal in G1.问题9：同态映射是否也保持了两个系统 的结构“相似性”？