Re: Hold and Equal

*To*: mathgroup at smc.vnet.net*Subject*: [mg73756] Re: Hold and Equal*From*: "dimitris" <dimmechan at yahoo.com>*Date*: Tue, 27 Feb 2007 05:53:43 -0500 (EST)*References*: <erufqm$s7j$1@smc.vnet.net>

Hello Murray. (*everything is converted to InputForm*) Is something like the following what you want? In[27]:= (HoldForm[#1 = #2] & ) @@ ((a + b)^2 == Expand[(a + b)^2]) Out[27]= HoldForm[(a + b)^2 = a^2 + 2*a*b + b^2] Dimitris =CF/=C7 Murray Eisenberg =DD=E3=F1=E1=F8=E5: > How can I produce in an Output cell (under program control) an > expression like the following, > > (a+b)^2 = a^2+ 2 a b + b^2 > > where instead of the usual Equal (==) I get a Set (=), as in tradit= ional > math notation? I want to input the unexpanded (a+b)^2 and have the > expansion done automatically. > > Of course, I can try something like the following: > > (a+b)^2 == Expand[(a+b)^2]) > > So how do I convert the == to =? Of course > > ((a + b)^2 == Expand[(a + b)^2]) /. Equal -> Set > > gives a Set::write error. And > > (Hold[(a + b)^2 == Expand[(a + b)^2]]) /. Equal -> Set > > doesn't actually evaluate the Expand part and leaves the "Hold" wrapper. > > > > > -- > Murray Eisenberg murray at math.umass.edu > Mathematics & Statistics Dept. > Lederle Graduate Research Tower phone 413 549-1020 (H) > University of Massachusetts 413 545-2859 (W) > 710 North Pleasant Street fax 413 545-1801 > Amherst, MA 01003-9305