Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Ordinals (continued)
sucex
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Metamath Proof Explorer
Ascii
Structured
Theorem
sucex
Description:
The successor of a set is a set.
(Contributed by
NM
, 30-Aug-1993)
Ref
Expression
Hypothesis
sucex.1
⊢
𝐴
∈ V
Assertion
sucex
⊢
suc
𝐴
∈ V
Proof
Step
Hyp
Ref
Expression
1
sucex.1
⊢
𝐴
∈ V
2
sucexg
⊢
(
𝐴
∈ V → suc
𝐴
∈ V )
3
1
2
ax-mp
⊢
suc
𝐴
∈ V