Let f:R→R and g:R→R be defined as
$$
\begin{aligned}
&f(x)=\left\{\begin{array}{lll}
\log _e x & , & x>0 \\
e^{-x} & , & x \leq 0
\end{array}\right. \text { and }\\
&g(x)=\left\{\begin{array}{cl}
x & , x \geq 0 \\
e^x & , x<0
\end{array} \text {. Then, gof: } \mathbf{R} \rightarrow \mathbf{R}\right. \text { is : }
\end{aligned}
$$