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	Could not format assertion : No typesetting found for |- _om C_ HF with typecode |-

Proof

Step	Hyp	Ref	Expression
1		omhf	Could not format ( x e. _om -> x e. HF ) : No typesetting found for |- ( x e. _om -> x e. HF ) with typecode |-
2	1	ssriv	Could not format _om C_ HF : No typesetting found for |- _om C_ HF with typecode |-