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Definition df-undef 7444
Description: Define the undefined value function, whose value at set 𝑠 is guaranteed not to be a member of 𝑠 (see pwuninel 7446). (Contributed by NM, 15-Sep-2011.)
Assertion
Ref Expression
df-undef Undef = (𝑠 ∈ V ↦ 𝒫 𝑠)

Detailed syntax breakdown of Definition df-undef
StepHypRef Expression
1 cund 7443 . 2 class Undef
2 vs . . 3 setvar 𝑠
3 cvv 3231 . . 3 class V
42cv 1522 . . . . 5 class 𝑠
54cuni 4468 . . . 4 class 𝑠
65cpw 4191 . . 3 class 𝒫 𝑠
72, 3, 6cmpt 4762 . 2 class (𝑠 ∈ V ↦ 𝒫 𝑠)
81, 7wceq 1523 1 wff Undef = (𝑠 ∈ V ↦ 𝒫 𝑠)
Colors of variables: wff setvar class
This definition is referenced by:  undefval  7447
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