Evaluate [ expr ] causes expr to be evaluated even if it appears as the argument of a function whose attributes specify that it should be held unevaluated.
Evaluate inside a Hold :
Evaluate works for arguments of any symbol with attributes HoldAll , HoldFirst , or HoldRest :
Since Attributes is HoldAll , use Evaluate to find the properties of the value of x :
Unprotect a system symbol to make a definition for it:
Force evaluation of the right-hand side of a delayed definition:
Build a function from an expression:
Evaluate does not work inside functions with attribute HoldAllComplete :
Use Unevaluated to temporarily treat a function as if it were HoldAll :
Evaluate works only on the first level, directly inside a held function:
Introduced in 1991 (2.0)
