Converted by
Mathematica
June 17, 2001
![[Graphics:../Images/Pratica7_gr_219.gif]](../Images/Pratica7_gr_219.gif)
![[Graphics:../Images/Pratica7_gr_222.gif]](../Images/Pratica7_gr_222.gif)
![[Graphics:../Images/Pratica7_gr_226.gif]](../Images/Pratica7_gr_226.gif)
![[Graphics:../Images/Pratica7_gr_230.gif]](../Images/Pratica7_gr_230.gif)