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from to .According to the definition of automorphism. We know is an automorphism of . Notice that for any , we have and .In fact for any , it is clearly . Also , Thus .Since , say , we have known . We can obtain, .. Hence the proof of ≤is plete. It is easy to see that for every, if and only if where is the center of (short for ).Let be the mapping defined by , we will prove that is a group homomorphism from G onto I(G) and that C is its kernel.For every , we can readily find that , that is to say, is onto. For any , since , so that is a group homomorphism from onto .Notice that for any and every , we have , ., , that is . We obtain, hence . Next, for any , we know , . for any , , so that , say , thus . Therefore . Since is a group homomorphism of G onto and , according to the FHT, we have .Theorem 3 is a conclusion which the FHT apply group of inner automorphisms of a group. . Let me see an example that Theorem 3 applies it.Exercise 3. is a group, the center of is and ,then .References: 1、近世代數(shù)初步,朱平天,李伯洪,鄒 園編,科學(xué)出版社,2001年8月第一版2、近世代數(shù)基礎(chǔ),劉邵學(xué),高等教育出版社,1999年10月第一版3、近世代數(shù)概論(上,下)王連祥,徐廣善譯,人民教育出版社,1979年12月第一版環(huán)與代數(shù),劉邵學(xué)著,科學(xué)出版社,1983年第一版近世代數(shù)引論, 馮克勤、李尚志、查建國(guó)、章璞編著,中國(guó)科技大學(xué)出版社2002年3月第二版群的基本同態(tài)定理的應(yīng)用李倩倩 劉志剛 楊立英(廣西師范學(xué)院 數(shù)學(xué)與計(jì)算機(jī)科學(xué)系, 南寧 530001) 摘要: 群的基本同態(tài)定理是群論研究中最常見、最有價(jià)值的結(jié)論之一。本文就該定理在群直積和內(nèi)同構(gòu)等方面的應(yīng)用進(jìn)行了討論并得到了一些有意義的結(jié)果。 關(guān)鍵詞:基本同態(tài)定理;直積;內(nèi)同構(gòu)。MR(2003)主題分類: 16W 中圖法分類: 文獻(xiàn)標(biāo)識(shí)法: A7 / 7