Converted by
Mathematica
June 17, 2001
![[Graphics:../Images/Pratica7_gr_156.gif]](../Images/Pratica7_gr_156.gif)
![[Graphics:../Images/Pratica7_gr_157.gif]](../Images/Pratica7_gr_157.gif)
![[Graphics:../Images/Pratica7_gr_158.gif]](../Images/Pratica7_gr_158.gif)
![[Graphics:../Images/Pratica7_gr_159.gif]](../Images/Pratica7_gr_159.gif)