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OneIdentity

OneIdentity
is an attribute that can be assigned to a symbol f to indicate that , , etc. are all equivalent to x for the purpose of pattern matching.
The pattern matches, because Times has attribute OneIdentity:
Any function with attribute OneIdentity will match:
The pattern matches, because Times has attribute OneIdentity:
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Any function with attribute OneIdentity will match:
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OneIdentity allows defaults to apply to expressions that do not involve Times at all:
For Flat functions, any sequence of arguments will match:
When f is both Flat and OneIdentity, a and are identical for pattern matching:
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