摘要 : In tins paper we mainly survey results obtained in [MM3]. Forexample, we give an elementary proof of two versions of Koebe 1/4 theorem foranalytic functions (see Theorem 1.2 and Theorem 1.4 below). We also showa version of the Koe... 展开 In tins paper we mainly survey results obtained in [MM3]. Forexample, we give an elementary proof of two versions of Koebe 1/4 theorem foranalytic functions (see Theorem 1.2 and Theorem 1.4 below). We also showa version of the Koebe theorem for quasiregular harmonic functions. As anapplication, we show that holomorphic functions (more generally quasiregularharmonic functions) and their modulus have similar behavior in a certain sense. 收起