Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Ordinals
0ellim
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limelon
Metamath Proof Explorer
Ascii
Structured
Theorem
0ellim
Description:
A limit ordinal contains the empty set.
(Contributed by
NM
, 15-May-1994)
Ref
Expression
Assertion
0ellim
⊢
( Lim
𝐴
→ ∅ ∈
𝐴
)
Proof
Step
Hyp
Ref
Expression
1
dflim2
⊢
( Lim
𝐴
↔ ( Ord
𝐴
∧ ∅ ∈
𝐴
∧
𝐴
=
∪
𝐴
) )
2
1
simp2bi
⊢
( Lim
𝐴
→ ∅ ∈
𝐴
)