Re: Problem with Function (there isn't any...)
- To: mathgroup at yoda.ncsa.uiuc.edu
 - Subject: Re: Problem with Function (there isn't any...)
 - From: decide!bobk at uunet.UU.NET (Bob Korsan)
 - Date: Mon, 8 Oct 90 14:16:06 PDT
 
If you further define
In[1]:= h=Function[x,x + -x^2]
Out[1]:= Function[x, x- x^2]
In[2]:= h'[2]
Out[2]:= -3
The trick is that Subtract is not associative and hence
In[3]:= D[Funcion[x, x-x^2],x]
                             (1,0)     2            (0,1)    2
Out[3]:= Function[x, Subtract     [x, x ] + Subtract    [x, x  ] 2 x]
All in all, this is the reason why languages like APL have a different
symbol which is used for negation and for subtraction. They are different
concepts.
Peace
Bob Korsan