Metamath Proof Explorer


Theorem ndmico

Description: The closed-below, open-above interval function's value is empty outside of its domain. (Contributed by Glauco Siliprandi, 2-Jan-2022)

Ref Expression
Assertion ndmico ⊢ ¬ A ∈ ℝ * ∧ B ∈ ℝ * → A B = ∅

Proof

Step Hyp Ref Expression
1 dmico ⊢ dom ⁡ . = ℝ * × ℝ *
2 1 ndmov ⊢ ¬ A ∈ ℝ * ∧ B ∈ ℝ * → A B = ∅