Metamath Proof Explorer


Theorem lttri5d

Description: Not equal and not larger implies smaller. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses lttri5d.a ⊢ φ → A ∈ ℝ
lttri5d.b ⊢ φ → B ∈ ℝ
lttri5d.aneb ⊢ φ → A ≠ B
lttri5d.nlt ⊢ φ → ¬ B < A
Assertion lttri5d ⊢ φ → A < B

Proof

Step Hyp Ref Expression
1 lttri5d.a ⊢ φ → A ∈ ℝ
2 lttri5d.b ⊢ φ → B ∈ ℝ
3 lttri5d.aneb ⊢ φ → A ≠ B
4 lttri5d.nlt ⊢ φ → ¬ B < A
5 1 rexrd ⊢ φ → A ∈ ℝ *
6 2 rexrd ⊢ φ → B ∈ ℝ *
7 5 6 3 4 xrlttri5d ⊢ φ → A < B