Re: Q: How to force an Equal[]
- Subject: [mg3358] Re: Q: How to force an Equal[]
- From: johan at isy.liu.se (Johan Gunnarsson)
- Date: 29 Feb 1996 15:59:27 -0600
- Approved: usenet@wri.com
- Distribution: local
- Newsgroups: wri.mathgroup
- Organization: Linkoping University, Dept. of EE, Division of Automatic Control
- Sender: daemon at wri.com
Gerd Lanfermann wrote: > > 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) Try y1===y2 instead. -- _____________________________________________________ Johan Gunnarsson | Division of Automatic Control /|\ Dept. of EE, Linkoping University \|/ S-581 83 Linkoping, Sweden /|\ Tel: +46 13 282913 / | \ Fax: +46 13 282622 () | () Email: johan at isy.liu.se WWW: http://control.isy.liu.se/~johan