The routine tname returns the name of the parameter in the parametric equations of the line obj. It returns either a name or FAIL.

The command with(geom3d,tname) allows the use of the abbreviated form of this command.

$\mathrm{with}\left(\mathrm{geom3d}\right)\:$

$\mathrm{\_EnvTName}≔'t'\:$

$\mathrm{point}\left(A\,0\,0\,0\right),\mathrm{point}\left(B\,1\,1\,11\right)\:$

$\mathrm{line}\left(l\,\left[A\,B\right]\right)$

$l$

$\mathrm{detail}\left(l\right)$

$\begin{array}{ll}\text{name of the object}& l\\ \text{form of the object}& \mathrm{line3d}\\ \text{equation of the line}& \left[\mathrm{\_x}=t\,\mathrm{\_y}=t\,\mathrm{\_z}=11t\right]\end{array}$

$\mathrm{tname}\left(l\right)$

$t$