Undiscovered Bug?

*To*: mathgroup at smc.vnet.net*Subject*: [mg46862] Undiscovered Bug?*From*: Harold.Noffke at wpafb.af.mil (Harold Noffke)*Date*: Fri, 12 Mar 2004 02:02:46 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

MathGroup: In Mathematica 5.0.1 with Windows 2000, I mistakenly used the [[{}]] operator on x/y. I was expecting an error, but I kept getting unusual results as shown in In/Out's 2 to 5 below. Have I stumbled on a bug, or is there a way to make sense out of this? In[1]:= TreeForm[x/y] Out[1]//TreeForm= Times[x, | ] Power[y, -1] In[2]:= (x/y)[[{2,2}]] Out[2]= -2 y In[3]:= (x/y)[[{1,2,1}]] 2 x Out[3]= -- y In[4]:= (x/y)[[{2, 2, 2, 2}]] -4 Out[4]= y In[5]:= (x/y)[[{2, 1, 1, 0, 2, 2, 0}]] 2 2 Times x Out[5]= --------- 3 y Regards, Harold

**Follow-Ups**:**Re: Undiscovered Bug?***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>