I usually parameterise a curve as $\Gamma = \Gamma(s) = (x_0(s)), y_0(s), u_0(s)) = (s, 0, \sin(s))$, where $s$ is a free parameter.
I now have the following parameterised curve:
$$ \Gamma(s) = \begin{cases} (s,0, \color{black}{\sin(s)}) & s\in [0,\infty) \\ (0,-s, \color{black}{\sin(-s)}) & s\in (-\infty,0] \end{cases}$$
If I put bounds on a parameter, as was done here, is it still a free parameter?