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Definition df-uni 4044
Description: Define the union of a class i.e. the collection of all members of the members of the class. Definition 5.5 of [TakeutiZaring] p. 16. For ?Error: 1 , 3 } , { 1 , 8 } } = { 1 , 3 , 8 } ^ This math symbol is not active (i.e. was not declared in this scope). example, U.{{1,3},{1,8}}={1,3,8} (ex-uni 21785). This is similar to the union of two classes df-un 3314. (Contributed by NM, 23-Aug-1993.)
Assertion
Ref Expression
df-uni
Distinct variable group:   , ,

Detailed syntax breakdown of Definition df-uni
StepHypRef Expression
1 cA . . 3
21cuni 4043 . 2
3 vx . . . . . 6
4 vy . . . . . 6
53, 4wel 1729 . . . . 5
64cv 1653 . . . . . 6
76, 1wcel 1728 . . . . 5
85, 7wa 360 . . . 4
98, 4wex 1551 . . 3
109, 3cab 2429 . 2
112, 10wceq 1654 1
Colors of variables: wff set class
This definition is referenced by:  dfuni2  4045  eluni  4046  unipr  4056  csbuni  4070  csbunigOLD  4071  uniuni  4757  csbunigVD  29251
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