A Non explicit counterexample to a problem of quasi-normality
Abstract
In 1986, S.Y. Li and H.Xie proved the following theorem:Let k>=2 and let F be a family of functions meromorphic in some domain D, all of whose zeros are of multiplicity at least k. Then F is normal if and only if the family Fk=f(k)/(1+|fk+1|):f in F is locally uniformly bounded in D. Here we give, in the case k=2, a counterexample to show that if the condition on the multiplicities of the zeros is omitted, then the local uniform boundedness of F2 does not imply even quasi-normality. In addition, we give a simpler proof for the Li-Xie Theorem that does not use Nevanlinna Theory which was used in the original proof.
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