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Re: What is @@@?

• To: mathgroup at smc.vnet.net
• Subject: [mg87438] Re: What is @@@?
• From: Bill Rowe <readnews at sbcglobal.net>
• Date: Thu, 10 Apr 2008 02:15:57 -0400 (EDT)

On 4/9/08 at 5:56 AM, siegman at stanford.edu (AES) wrote:

>The link presented earlier in this thread,

><http://documents.wolfram.com/mathematica/book/section-A.2.7>

>starts off with:

>A.2.7 Operator Input Forms

>Characters that are not letters, letter-like forms or structural
>elements are treated by Mathematica as operators.

>Since letters are not numbers (i.e., numerals); the formal
>documentation on "letter-like forms" makes no mention of numbers;
>and I don't think that numbers are "structural elements" (didn't
>look that one up, actually), does this mean that Mathematica treats
>"3" as an operator, so that inputs like

>a 3 b    or    a3b

>are taken as some kind of operator connecting a and b, or operating
>on b?

No, Mathematica does not treat the "3" in either expression
above as some kind of operator.  The comments you quote above
doesn't apply to a3b since this is a string of characters
covered by other parts of the documentation covering naming rules.

And in the case of a 3 b, the operator is the space character,
i.e., the implied multiplication not the "3". Again, there are
other parts of the documentation covering what is regarded as a
number, expression, variable etc that takes precedence over the
portion you quoted.