Theorem clel2 1888

Description: An alternate definition of class membership when the class is a set.

Hypothesis

Ref	Expression
clel2.1	|- A e. V

Assertion

Ref	Expression
clel2	|- (A e. B <-> A.x(x = A -> x e. B))

Distinct variable groups:   x,A   x,B

Proof of Theorem clel2

Step	Hyp	Ref	Expression
1		clel2.1	. . 3 |- A e. V
2		eleq1 1532	. . 3 |- (x = A -> (x e. B <-> A e. B))
3	1, 2	ceqsalv 1824	. 2 |- (A.x(x = A -> x e. B) <-> A e. B)
4	3	bicomi 172	1 |- (A e. B <-> A.x(x = A -> x e. B))

Syntax hints:   -> wi 3   <-> wb 146  A.wal 953   = wceq 955   e. wcel 957  Vcvv 1808

This theorem is referenced by:  snss 2458

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-gen 962  ax-12 967  ax-17 970  ax-4 972  ax-5o 974  ax-6o 977  ax-9o 1122  ax-ext 1458

This theorem depends on definitions:  df-bi 147  df-an 225  df-ex 980  df-sb 1171  df-clab 1463  df-cleq 1468  df-clel 1471  df-v 1809

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