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Re: How to define an auto-Collect function (fwd)

On Thu, 3 Jul 1997, Roland Franzius wrote:

> just define
> prd/: prd[a_,b_]+prd[a_,c]:=prd[a,b+c]
> Your example takes 1.9 s on my old 486dx2/66
> r.franzius

Hi Roland,

Thanks for the input on my question. Unfortunately, I think you might have
made a mistake. First, there is no difference between the statements

prd /: prd[a_,b_]+prd[a_,c_]:=prd[a,b+c]



Try out both statements and check ??prd. Secondly, I think you might have
missed the underscore after the c in the second prd. Without the
underscore, the collecting function won't work, and my example will not
work. As a test of your definition, make sure that 




Note that without the underscore, my example will run much faster, since
there is less generality in the prd definition.

Again, thanks for your suggestion.

Carl Woll

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