Metamath Proof Explorer


Theorem ltnr

Description: 'Less than' is irreflexive. (Contributed by NM, 18-Aug-1999)

Ref Expression
Assertion ltnr ( 𝐴 ∈ ℝ → ¬ 𝐴 < 𝐴 )

Proof

Step Hyp Ref Expression
1 ltso < Or ℝ
2 sonr ( ( < Or ℝ ∧ 𝐴 ∈ ℝ ) → ¬ 𝐴 < 𝐴 )
3 1 2 mpan ( 𝐴 ∈ ℝ → ¬ 𝐴 < 𝐴 )