14: c:=(u+v)^4 ;
      4      3        2  2        3    4
c := u  + 4*u *v + 6*u *v  + 4*u*v  + v
15: cu:=df(c,u) ;
          3      2          2    3
cu := 4*(u  + 3*u *v + 3*u*v  + v )
16: cv:=df(c,v) ;
          3      2          2    3
cv := 4*(u  + 3*u *v + 3*u*v  + v )
17: write "=====> submit number ", 3, " done <=====" ;
=====> submit number 3 done <=====
18: 
