Option ExcludedForms

*To*: mathgroup at smc.vnet.net*Subject*: [mg21736] Option ExcludedForms*From*: Blimbaum Jerry DLPC <BlimbaumJE at ncsc.navy.mil>*Date*: Wed, 26 Jan 2000 03:45:36 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

A question was asked recently about a problem with Simplify and FullSimplify concerning the following expression: expr =(3*x + (x - y)*Log[x] + (x - y)*Log[-1 + y/x])/(x - y) and why didnt these commands simply divide thru the (x-y) terms. The following does that: FullSimplify[ expr,ExcludedForms->{x-y}] I have found ExcludedForms quite helpful but wondered why is this only available for FullSimplify and not Simplify. One of the responses I got back was that Simplify[expr,TransformationFunctions->{x-y}] should do the same thing but it doesnt. So my question remains why this Exclusion option is only available for FullSimplify? thanks. jerry blimbaum