differential operator in maxima



"tws"  [31/07/03 17:10 +0400]:
> Hi All.
>
> 
> Also i wonder how could i define a function which argument and value are at 
> their turn functions, for example the following symmetrizing linear operator:
> 
> AF(x) = 1/2(F(x)+F(-x))
> 

I don't know much, but A(F,x) := (F(x)+F(-x))/2 seem to be working.
Milan

> In Maple this would be A:=F->unapply(1/2*(F(x)+F(-x)),x); 
> then A(exp)(x) = 1/2*(exp(x)+exp(-x)).
> In Maxima expression like A(F)(x) leads to error.
> 
> Please excuse me if these questions are too stupid.
> 
> Regards, tws.
>