Theorem 0finon

Description: 0 is a finite ordinal. See peano1 . (Contributed by RP, 27-Sep-2023)

	Ref	Expression
Assertion	0finon	⊢ ∅ ∈ ( On ∩ Fin )

Proof

Step	Hyp	Ref	Expression
1		peano1	⊢ ∅ ∈ ω
2		onfin2	⊢ ω = ( On ∩ Fin )
3	1 2	eleqtri	⊢ ∅ ∈ ( On ∩ Fin )