Assume that we are given $M=R e^{+}$and the function on the positive reals given by $F(x)=x / 2$. Use $F$ to write the recursive definition of a function $r: N a t \rightarrow \operatorname{Re}^{+}$satisfying $r(0)=1$. Also, compute the values of $r(k)$ for
$$
k=s(0), \quad s(s(0)), \quad s(s(s(0))), \quad s(s(s(s(0)))), \quad s(s(s(s(s(0))))) .
$$