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Definition df-undef 6535
Description: Define the undefined value function, whose value at set  s is guaranteed not to be a member of 
s (see pwuninel 6537). (Contributed by NM, 15-Sep-2011.)
Assertion
Ref Expression
df-undef  |-  Undef  =  ( s  e.  _V  |->  ~P
U. s )

Detailed syntax breakdown of Definition df-undef
StepHypRef Expression
1 cund 6533 . 2  class  Undef
2 vs . . 3  set  s
3 cvv 2948 . . 3  class  _V
42cv 1651 . . . . 5  class  s
54cuni 4007 . . . 4  class  U. s
65cpw 3791 . . 3  class  ~P U. s
72, 3, 6cmpt 4258 . 2  class  ( s  e.  _V  |->  ~P U. s )
81, 7wceq 1652 1  wff  Undef  =  ( s  e.  _V  |->  ~P
U. s )
Colors of variables: wff set class
This definition is referenced by:  undefval  6538
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