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Topic: Default value in pattern matching
Replies: 1   Last Post: Jan 28, 2014 6:05 AM

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Yi Wang

Posts: 33
Registered: 3/30/12
Re: Default value in pattern matching
Posted: Jan 28, 2014 6:05 AM
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Actually, the property I looked after is not that Plus has a default value (though it is an insignificant part of the story), but that Plus has attribute OneIdentity, which affects pattern matching.

SetAttributes[myPlus, OneIdentity]

Default[myPlus] = 0;
a /. {myPlus[a, b_.] -> "matched"}

Out[] = "matched"

The example given here is not exactly as the one in my question. But this is enough for my purpose.

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