Metamath Proof Explorer


Theorem xrltned

Description: 'Less than' implies not equal. (Contributed by Glauco Siliprandi, 21-Nov-2020)

Ref Expression
Hypotheses xrltned.1 ⊢ φ → A ∈ ℝ *
xrltned.2 ⊢ φ → B ∈ ℝ *
xrltned.3 ⊢ φ → A < B
Assertion xrltned ⊢ φ → A ≠ B

Proof

Step Hyp Ref Expression
1 xrltned.1 ⊢ φ → A ∈ ℝ *
2 xrltned.2 ⊢ φ → B ∈ ℝ *
3 xrltned.3 ⊢ φ → A < B
4 1 2 3 xrgtned ⊢ φ → B ≠ A
5 4 necomd ⊢ φ → A ≠ B