Biholomorphism
In the mathematical theory of functions of one or more complex variables, and also in complex algebraic geometry, a biholomorphism or biholomorphic function is a bijective holomorphic function whose inverse is also holomorphic. == Formal definition == Formally, a biholomorphic function is a function ϕ {\displaystyle \phi } defined on an open subset U of the n {\displaystyle n} -dimensional complex space Cn with values in Cn which is holomorphic and one-to-one, such that its image is an open set V {\displaystyle V} in Cn and the inverse ϕ − 1 : V → U {\displaystyle \phi ^{-1}:V\to U} is also holomorphic.