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Q: How to force an Equal[]

  • Subject: [mg3332] Q: How to force an Equal[]
  • From: s997826 at umslvma.umsl.edu ("Gerd Lanfermann")
  • Date: 28 Feb 1996 08:45:20 -0600
  • Approved: usenet@wri.com
  • Distribution: local
  • Newsgroups: wri.mathgroup
  • Organization: Wolfram Research, Inc.
  • Sender: daemon at wri.com

Hi there,

this should be a nice relaxing one. How can I force Mma to evaluate 
the equal expression, regardless of what values Word or Number 
stand for. I just want a false in the second case (y1==y2).


In[]:=
x1={car, nose, 2334.34};
x2={dummy, 3.1415, 8}; 
x3={eye,345,567};

In[]:=
y1=Map[Head,x1]//.{Symbol->Word,Integer->Number, Real->Number}
y2=Map[Head,x2]//.{Symbol->Word,Integer->Number, Real->Number}
y3=Map[Head,x3]//.{Symbol->Word,Integer->Number, Real->Number}

Out[]:=
{Word, Word, Number}
{Word, Number, Number}
{Word, Number, Number}

Here we go:

y2==y3

gives me as desired
True

But this guy just returns the expressions:
y1==y2

{Word, Word, Number} == {Word, Number, Number}

I would like to see a False here.It works when I do 
{Symbol->"Word", ...}, converting it to Strings. But I wouldn't
call that a nice style of writing inMma.

Thanks
Gerd




Gerd Lanfermann
840 N.Taylor
St.Louis, Mo. 63122
USA
phone: (314) / 822 4518
email: s997826 at umslvma.umsl.edu          (University of Missouri, St.Louis)
       lanfer at sirius.physik.fu-berlin.de (Freie Universitaet Berlin)


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