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Metamath Proof Explorer


Theorem limuni2

Description: The union of a limit ordinal is a limit ordinal. (Contributed by NM, 19-Sep-2006)

Ref Expression
Assertion limuni2 Lim A Lim A

Proof

Step Hyp Ref Expression
1 limuni Lim A A = A
2 limeq A = A Lim A Lim A
3 1 2 syl Lim A Lim A Lim A
4 3 ibi Lim A Lim A