Converted by
Mathematica
June 17, 2001
![[Graphics:../Images/Pratica7_gr_213.gif]](../Images/Pratica7_gr_213.gif)
![[Graphics:../Images/Pratica7_gr_214.gif]](../Images/Pratica7_gr_214.gif)
![[Graphics:../Images/Pratica7_gr_215.gif]](../Images/Pratica7_gr_215.gif)
![[Graphics:../Images/Pratica7_gr_216.gif]](../Images/Pratica7_gr_216.gif)