This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)


assigns rhs to be the value of lhs, and associates the assignment with symbols that occur at level one in lhs.
  • makes an assignment associated with f. makes an assignment associated instead with g.
  • UpSet associates an assignment with all the distinct symbols that occur either directly as arguments of lhs, or as the heads of arguments of lhs.
Define a symbolic property of a symbol:
Define a symbolic property of a symbol:
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defines upvalues:
If several symbols appear in the left-hand side, upvalues for all of them are defined:
Build a database of exchange rates:
defines upvalues in the same way as using a tag does:
defines upvalues; defines downvalues:
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