| Let F be a family of meromorphic functions on the plain domain D, a1 and a2,a3 are three distinct complex numbers. If for every f∈F,f(z) = a1(?)fk(z) = a1,f∈{a1,a2}(?) fk∈{a1,a2}, and the zeros of f-a1 are of multiplicity at least k, then F is normal on D. |
