Re: D[...] change in 5.1

*To*: mathgroup at smc.vnet.net*Subject*: [mg58697] Re: D[...] change in 5.1*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Fri, 15 Jul 2005 03:02:12 -0400 (EDT)*Organization*: The Open University, Milton Keynes, England*References*: <db57qa$4ri$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Alexei Akolzin wrote: > Hi, > > In previous version two lines below seemed to work as intended: > > In: > n /: D[n[i_], x[j_], NonConstants -> {n,r}] := (1/r)( d[i,j] - n[i] n[j] ); > D[ 1 + n[k], x[l] ] > > Out: (-n[k] n[l] + d[k,l]) \ r > > But now in ver 5.1 I get something like: > Out: D[n, x[l], NonConstants -> {J, r, n}] (1) > > The funny part is that D[ n[k], x[l] ] is recognized and substituted by the > expression associated with definition of n. > > I wonder whether there is a possibility to get Mathematica 5.1 recognize > n[k] as an indexed symbol n. > > Thanks. > Alexei Akolzin. > Hi Alexei, Have you posted the correct expression? I am asking because here what I get with Mathematica 5.1.1: In[1]:= n /: D[n[i_], x[j_], NonConstants -> {n, r}] := (1/r)*(d[i, j] - n[i]*n[j]); In[2]:= D[1 + n[k], x[l]] Out[2]= 0 In[3]:= Information["n", LongForm -> False] n n /: D[n[i_], x[j_], NonConstants -> {n, r}] := (1/r)*(d[i, j] - n[i]*n[j]) In[4]:= $Version Out[4]= "5.1 for Microsoft Windows (January 27, 2005)" Best regards, /J.M.