Converted by
Mathematica
June 17, 2001
![[Graphics:../Images/Pratica7_gr_141.gif]](../Images/Pratica7_gr_141.gif)
![[Graphics:../Images/Pratica7_gr_142.gif]](../Images/Pratica7_gr_142.gif)
![[Graphics:../Images/Pratica7_gr_143.gif]](../Images/Pratica7_gr_143.gif)
![[Graphics:../Images/Pratica7_gr_144.gif]](../Images/Pratica7_gr_144.gif)