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Metamath Proof Explorer

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