Expanding summation




On Mon, 20 Jul 2009, Bill Maier wrote:

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< I'm having trouble expanding a summation.
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<  
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< I start with ex1:sum(f[i,j],i,1,n);
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< Then I substitute for n with ex2:subst(4,n,ex1);
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<  
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< I'd like to see all 4 terms written out like f[1,j]+f[2,j]+f[3,j]+f[4,j], but the expression is always written with the summation sign. I've tried expand(), expandwrt(), ev(), etc. Can someone tell me how to do this?

Try:

ex1,n=4,nouns;

Leo

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