Theorem 7on

Description: Ordinal 7 is an ordinal number. (Contributed by BTernaryTau, 4-Sep-2026)

	Ref	Expression
Assertion	7on	Could not format assertion : No typesetting found for |- 7o e. On with typecode |-

Proof

Step	Hyp	Ref	Expression
1		df-7o	Could not format 7o = suc 6o : No typesetting found for |- 7o = suc 6o with typecode |-
2		6on	Could not format 6o e. On : No typesetting found for |- 6o e. On with typecode |-
3	2	onsuci	Could not format suc 6o e. On : No typesetting found for |- suc 6o e. On with typecode |-
4	1 3	eqeltri	Could not format 7o e. On : No typesetting found for |- 7o e. On with typecode |-