Theorem 3re

Description: The number 3 is real. (Contributed by NM, 27-May-1999)

	Ref	Expression
Assertion	3re	⊢ 3 ∈ ℝ

Proof

Step	Hyp	Ref	Expression
1		df-3	⊢ 3 = ( 2 + 1 )
2		2re	⊢ 2 ∈ ℝ
3		1re	⊢ 1 ∈ ℝ
4	2 3	readdcli	⊢ ( 2 + 1 ) ∈ ℝ
5	1 4	eqeltri	⊢ 3 ∈ ℝ