gives a list of transformation rules corresponding to all downvalues defined for the symbol f.
Details and Options
- You can specify the downvalues for f by making an assignment of the form DownValues[f]=list.
- The list returned by DownValues has elements of the form HoldPattern[lhs]:>rhs.
Examplesopen allclose all
Basic Examples (1)
Define values for a function f:
These are the downvalues associated with f:
DownValues returns rules corresponding to definitions made for a symbol:
DownValues can be used to set the values directly:
The resulting rules are in the order given:
Now reorder the definitions:
Copy a symbol's definitions to another symbol:
Properties & Relations (4)
Values can be defined by immediate or delayed assignments:
HoldPattern is used to protect the rules from their own definitions:
Definition and Information display downvalues but do not return them as values:
DownValues returns a value that can be used in a program:
Evaluation of an expression involves applying rules for its head:
Introduced in 1991
Updated in 1996