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Re: ClearAll error message

  • To: mathgroup at
  • Subject: [mg92363] Re: ClearAll error message
  • From: Albert Retey <awnl at>
  • Date: Mon, 29 Sep 2008 07:06:57 -0400 (EDT)
  • References: <gbnpep$pr3$>

carlos at wrote:
> Just out of curiosity.  The following ClearAll works as expected.
>   name=Symbol["A"]; ClearAll[name];
> But this elicits an error message:
>   ClearAll[Symbol["A"]];
> Why?  A non-standard argument evaluation?

Yes, since Clear needs to work with symbols which have a value, it has
attribute HoldAll:


This should work, provided there is no OwnValue for A:


if you want to be on the save side, you should make it work even if
there is an OwnValue for A, which is more elaborate:

Apply[ClearAll,ToExpression["A", InputForm, Hold]]



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