In complex analysis, a mathematical discipline, the fundamental normality test gives sufficient conditions to test the normality of a family of analytic functions. It is another name for the stronger version of Montel's theorem.
Statement Let F {\displaystyle {\mathcal {F}}} be a family of analytic functions defined on a domain Ω {\displaystyle \Omega } . If there are two fixed complex numbers a and b such that for all ƒ ∈ F {\displaystyle {\mathcal {F}}} and all x ∈ Ω {\displaystyle x\in \Omega } , f ( x ) ∉ { a , b } {\displaystyle f(x)\not \in \{a,b\}} , then F {\displaystyle {\mathcal {F}}} is a normal family on Ω {\displaystyle \Omega } . The proof relies on properties of the elliptic modular function and can be found here: J. L. Schiff (1993). Normal Families. Springer-Verlag. ISBN 0-387-97967-0.
See also Montel's theorem
