Theorem 7onn

Description: The ordinal 7 is a natural number. (Contributed by BTernaryTau, 4-Sep-2026)

	Ref	Expression
Assertion	7onn	Could not format assertion : No typesetting found for |- 7o e. _om 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		6onn	Could not format 6o e. _om : No typesetting found for |- 6o e. _om with typecode |-
3		peano2	Could not format ( 6o e. _om -> suc 6o e. _om ) : No typesetting found for |- ( 6o e. _om -> suc 6o e. _om ) with typecode |-
4	2 3	ax-mp	Could not format suc 6o e. _om : No typesetting found for |- suc 6o e. _om with typecode |-
5	1 4	eqeltri	Could not format 7o e. _om : No typesetting found for |- 7o e. _om with typecode |-