Wolfram Language & System 10.4 (2016)|Legacy Documentation

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SetDelayed


assigns rhs to be the delayed value of lhs. rhs is maintained in an unevaluated form. When lhs appears, it is replaced by rhs, evaluated afresh each time.

DetailsDetails

  • SetDelayed has attribute HoldAll, rather than HoldFirst.
  • You can make assignments of the form , where test gives conditions for the applicability of each transformation rule. You can make several assignments with the same lhs but different forms of test.
  • returns Null if the assignment specified can be performed, and returns $Failed otherwise.
Introduced in 1988
(1.0)