Indexed object as a variable

*To*: mathgroup at smc.vnet.net*Subject*: [mg5287] Indexed object as a variable*From*: helgebe at ifi.uio.no (Helge Berglann)*Date*: Sat, 23 Nov 1996 01:44:32 -0500*Organization*: SUM/Bio*Sender*: owner-wri-mathgroup at wolfram.com

Is it possible to declare an indexed object in such a way that it behaves like a variable and not a constant?. That is in the following example to give the answer Dt[a1] Dt[x[1]] + Dt[a2] Dt[x[2]] Mathematica 2.2 for DEC RISC Copyright 1988-93 Wolfram Research, Inc. -- Motif graphics initialized -- In[1]:= eq = a1 x[1] + a2 x[2] Out[1]= a1 x[1] + a2 x[2] In[2]:= Dt[eq] Out[2]= Dt[a1] x[1] + Dt[a2] x[2]