Theorem 1lt10

Description: 1 is less than 10. (Contributed by NM, 7-Nov-2012) (Revised by Mario Carneiro, 9-Mar-2015) (Revised by AV, 8-Sep-2021) (Proof shortened by Umit Teoman Dogan, 10-Jun-2026)

	Ref	Expression
Assertion	1lt10	$$⊢1<10$$

Proof

Step	Hyp	Ref	Expression
1		1nn0	$$⊢1\in {\mathbb{N}}_0$$
2		1re	$$⊢1\in ℝ$$
3		9re	$$⊢9\in ℝ$$
4		1lt9	$$⊢1<9$$
5	2 3 4	ltleii	$$⊢1\le 9$$
6	1 5	le9lt10	$$⊢1<10$$