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Re: List of function-heads

  • To: mathgroup at smc.vnet.net
  • Subject: [mg17076] Re: List of function-heads
  • From: dreeves at flip.eecs.umich.edu (Daniel Reeves)
  • Date: Sat, 17 Apr 1999 03:34:49 -0400
  • References: <7f1g3u$ku0@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

> In[1]:=fl=Table[a[i][x_],{i,2}]
> Out[1]={{a[1][x_],a[2][x_]}
> 
> But then I can't write:
> 
> fl={x^2,x-1}

Evaluate[fl] = {x^2,x-1}

This is necessary because Set (=) has attribute HoldFirst.

> Is there a way to get it working? I tried Thread, MapThread and some
> more but didn't find a solution.

MapThread also works:
MapThread[Set,{fl,{x^2,x-1}}]

With Thread you have the problem of Set's HoldFirst again.
That can be worked around like this:
Thread[myset[fl,{x^2,x-1}]] /. myset -> Set

--    --    --    --    --    --    --    --    --    --    --    -- 
Daniel Reeves               http://ai.eecs.umich.edu/people/dreeves/

"The good Christian should beware of mathematicians and all those who
make empty prophecies.  The danger already exists that mathematicians
have made a covenant with the devil to darken the spirit and confine
man in the bonds of Hell."
                -- St. Augustine


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