This question is related to this question: "[Solutions of equations characterizing a complex structure.][1]" Where, here we suppose the Euclidean space instead of Sphere and the following equations happen if and only if the almost complex structure $J_{\delta ,\beta}$ (defined as the introduced structure in [this question][1]) is a complex structure on $T\mathbb{R}^{2n}$(the tangent space of $\mathbb{R}^{2n}$). Let $\mathbb{R}^{2n}$ be the Euclidean $2n$ dimensional space and $(x^1,...,x^n,y^1,...,y^n)$ be its coordinate system. Suppose $u=\frac{\beta}{\delta}$ and $v=\frac{1}{\delta}$ where $\beta , \delta$ are real-valued functions on $\mathbb{R}^{2n}$. Is there any other solutions except constant functions satisfying the following Equations? $$\frac{\partial v}{\partial x^l}+ v\frac{\partial u}{\partial y^l} +u\frac{\partial v}{\partial y^l}=0,\hspace{1cm} \forall l, \hspace{1cm} 1\leq l\leq n$$ and $$\frac{\partial u}{\partial x^l}- v\frac{\partial v}{\partial y^l} +u\frac{\partial u}{\partial y^l}=0,\hspace{1cm} \forall l, \hspace{1cm} 1\leq l\leq n$$ [1]: http://mathoverflow.net/questions/230574/solutions-of-equations-characterizing-a-complex-structure