Metamath Proof Explorer


Theorem ltso

Description: 'Less than' is a strict ordering. (Contributed by NM, 19-Jan-1997)

Ref Expression
Assertion ltso < Or ℝ

Proof

Step Hyp Ref Expression
1 axlttri ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → ( 𝑥 < 𝑦 ↔ ¬ ( 𝑥 = 𝑦𝑦 < 𝑥 ) ) )
2 lttr ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ∧ 𝑧 ∈ ℝ ) → ( ( 𝑥 < 𝑦𝑦 < 𝑧 ) → 𝑥 < 𝑧 ) )
3 1 2 isso2i < Or ℝ