Theorem peano3OLD

Description: Obsolete version of peano3 as of 10-Jun-2026. (Contributed by NM, 3-Sep-2003) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	peano3OLD	$$⊢A\in \mathrm{\omega }\to \mathrm{suc}A\ne \varnothing$$

Proof

Step	Hyp	Ref	Expression
1		nsuceq0	$$⊢\mathrm{suc}A\ne \varnothing$$
2	1	a1i	$$⊢A\in \mathrm{\omega }\to \mathrm{suc}A\ne \varnothing$$