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Metamath Proof Explorer

Theorem 0lt1o

Description: Ordinal zero is less than ordinal one. (Contributed by NM, 5-Jan-2005)

		Ref	Expression
	Assertion	0lt1o	⊢ ∅ ∈ 1_o

Step	Hyp	Ref	Expression
1		eqid	⊢ ∅ = ∅
2		el1o	⊢ ( ∅ ∈ 1_o ↔ ∅ = ∅ )
3	1 2	mpbir	⊢ ∅ ∈ 1_o