FullSimplify with Assumptions

*To*: mathgroup at smc.vnet.net*Subject*: [mg53339] FullSimplify with Assumptions*From*: "Goyder Dr HGD" <h.g.d.goyder at cranfield.ac.uk>*Date*: Thu, 6 Jan 2005 22:00:39 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

In the examples below I would expect FullSimplify to give L. However, I get results that depend on the symbols I use. It would appear that symbols x and y are treated differently. How can I force FullSimplify to use the LeafCount as the ComplexityFunction? In[14]:= r1 = FullSimplify[(L - L*y^2)/x^2, {-1 + x^2 + y^2 == 0}] Out[14]= (L - L*y^2)/x^2 In[15]:= r2 = FullSimplify[(L - L*x^2)/y^2, {-1 + x^2 + y^2 == 0}] Out[15]= L In[16]:= LeafCount[r1] Out[16]= 12 In[17]:= LeafCount[r2] Out[17]= 1 In[18]:= $Version Out[18]= "5.1 for Microsoft Windows (October 25, 2004)" Thanks for any comment Hugh Goyder -- This message has been scanned for viruses and dangerous content by the Cranfield MailScanner, and is believed to be clean.

**Follow-Ups**:**Re: FullSimplify with Assumptions***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>