Theorem 1lt5

Description: 1 is less than 5. (Contributed by Mario Carneiro, 15-Sep-2013)

	Ref	Expression
Assertion	1lt5	$$⊢1<5$$

Proof

Step	Hyp	Ref	Expression
1		1lt4	$$⊢1<4$$
2		4lt5	$$⊢4<5$$
3		1re	$$⊢1\in ℝ$$
4		4re	$$⊢4\in ℝ$$
5		5re	$$⊢5\in ℝ$$
6	3 4 5	lttri	$$⊢\left(1<4\wedge 4<5\right)\to 1<5$$
7	1 2 6	mp2an	$$⊢1<5$$