Re: Transformations in expressions

*To*: mathgroup at smc.vnet.net*Subject*: [mg91911] Re: Transformations in expressions*From*: Szabolcs Horvát <szhorvat at gmail.com>*Date*: Fri, 12 Sep 2008 05:29:34 -0400 (EDT)*Organization*: University of Bergen*References*: <gaar3o$16q$1@smc.vnet.net>

Miguel wrote: > Hi all, > How can I to transform a specific expression to other by substitution > of a part of it. > > For example, I want to transform the expression Log[x^2+y^3]/ > Sin[x^2+y^3] in Log[z]/Sin[z] by substitution x^2+y^3 --> z. > In[1]:= Log[x^2 + y^3]/Sin[x^2 + y^3] /. x^2 + y^3 -> z Out[1]= Csc[z] Log[z] > And other question: Is the new expression dependent of z. I see it is, > but how can I to programar it. > I don't really understand this second question ...