Theorem omsshf

Description: The class of finite ordinals is included in the class of hereditarily finite sets. (Contributed by Eric Schmidt, 26-Sep-2026)

	Ref	Expression
Assertion	omsshf	⊢ ω ⊆ HF

Proof

Step	Hyp	Ref	Expression
1		omhf	⊢ ( 𝑥 ∈ ω → 𝑥 ∈ HF )
2	1	ssriv	⊢ ω ⊆ HF