You must have already executed all the definitions above in the solution (pointP, pointQ, etc.) first.
![[Graphics:../Images/index_gr_110.gif]](../Images/index_gr_110.gif)
![[Graphics:../Images/index_gr_111.gif]](../Images/index_gr_111.gif)
![[Graphics:../Images/index_gr_112.gif]](../Images/index_gr_112.gif)
![[Graphics:../Images/index_gr_113.gif]](../Images/index_gr_113.gif){kind=small}
![[Graphics:../Images/index_gr_117.gif]](../Images/index_gr_117.gif)