Let $f_1: R \rightarrow R, f_2:[0, \infty) \rightarrow R, f_3: R \rightarrow R$ and $f_4: R \rightarrow[0, \infty)$ be defined by $ \begin{aligned} & f_1(x)=\left\{\begin{array}{ccc} |x| & \text { if } & x<0 \\ e^x & \text { if } & x \geq 0 \end{array}\right. \\ & f_2(x)=x^2 ; \\ & f_3(x)=\left\{\begin{array}{ccc} \sin x & \text { if } & x<0, \\ x & \text { if } & x \geq 0 \end{array}\right. \end{aligned} $ and $ f_4(x)=\left\{\begin{array}{ccc} f_2\left(f_1(x)\right) & \text { if } & x<0 \\ f_2\left(f_1(x)\right)-1 & \text { if } & x \geq 0 \end{array}\right. $