Theorem 6on

Description: Ordinal 6 is an ordinal number. (Contributed by BTernaryTau, 4-Sep-2026)

	Ref	Expression
Assertion	6on	Could not format assertion : No typesetting found for |- 6o e. On with typecode |-

Proof

Step	Hyp	Ref	Expression
1		df-6o	Could not format 6o = suc 5o : No typesetting found for |- 6o = suc 5o with typecode |-
2		5on	Could not format 5o e. On : No typesetting found for |- 5o e. On with typecode |-
3	2	onsuci	Could not format suc 5o e. On : No typesetting found for |- suc 5o e. On with typecode |-
4	1 3	eqeltri	Could not format 6o e. On : No typesetting found for |- 6o e. On with typecode |-