`diff'
------

diff(RAT[,VARN]*)

diff(RAT,VARLIST)
     :: Differentiate RAT successively by VAR's for the first form, or
     by variables in VARLIST for the second form.

RETURN
     expression

RAT
     rational expression which contains elementary functions.

VARN
     indeterminate

VARLIST
     list of indeterminates

   * Differentiate RAT successively by VAR's for the first form, or by
     variables in VARLIST for the second form.

   * differentiation is performed by the specified indeterminates
     (variables) from left to right.  diff(RAT,x,y) is the same as
     diff(diff(RAT,x),y).

     [0] diff((x+2*y)^2,x);
     2*x+4*y
     [1] diff((x+2*y)^2,x,y);
     4
     [2] diff(x/sin(log(x)+1),x);
     (sin(log(x)+1)-cos(log(x)+1))/(sin(log(x)+1)^2)
     [3] diff(sin(x),[x,x,x,x]);
     sin(x)

