Re: Why does _+_==2_ (or, why is HoldPattern required
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- Subject: [mg132245] Re: Why does _+_==2_ (or, why is HoldPattern required
- From: Alan G Isaac <alan.isaac at gmail.com>
- Date: Wed, 22 Jan 2014 03:31:46 -0500 (EST)
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On 1/20/2014 10:42 PM, Itai Seggev wrote: > MatchQ[x+x, _+_] would return False That is actually much less surprising to me: one expects evaluation of the first expression. What is quite surprising is that `_+_` does not stand for any+thing, `_*_` does not stand for any*thing, etc. (Not unless one uses HoldPattern.) I do not consider these "edge cases". As you say, a decision had to be made. I am just trying to understand the decision. Your answer that it treats all symbolic expressions equally is very likely a good answer in the end, but of course on its own it begs the question. Thanks, Alan Isaac
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- Why does _+_==2_ (or, why is HoldPattern required for sensible matching)?
- From: Alan <alan.isaac@gmail.com>
- Why does _+_==2_ (or, why is HoldPattern required for sensible matching)?