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MathGroup Archive 1998

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Re: [Q] How to get rid of {} ???

In article <6as8tj$>,
(Alessandro Rossi) wrote:

> Hi everyone again...
> I'm just curious to ask if is it possible to get rid of the {} simbols
> in a plain list of this kind {a1, a2, a3, ..., an} when you want to use
> the ordered sequence of a1, a2, a3, ..., an as arguments for a
> function.
> e.g.
> l
> If I have the following list:
> list={True, False, True}
> how can I computethe And Function of the three arguments of list:
> And[True, False, True]
> obviously 
> And[list]
> doesn't work...
> It seems to me a very simple problem, but at the same time I really can
> not solve it. Any samaritan willing to give me some indication to solve
> this "Columbus Egg"???
> Alessandro Rossi

Thd function Apply is what you are looking for.  In you example you
would write


or use the shorthand


Here are some examples (note the use of ## rather than # in the  pure
function of the last example):

In[1]:= And@@{x,y,z}

Out[1]= x&&y&&z

In[2]:= Apply[Plus,{x,y,z}]

Out[2]= x+y+z

In[3]:= Apply[f[##,y]&,{x,y,z}]

Out[3]= f[x,y,z,y]

David Reiss
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