Metamath Proof Explorer


Theorem mnfltd

Description: Minus infinity is less than any (finite) real. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypothesis mnfltd.a ⊢ φ → A ∈ ℝ
Assertion mnfltd ⊢ φ → −∞ < A

Proof

Step Hyp Ref Expression
1 mnfltd.a ⊢ φ → A ∈ ℝ
2 mnflt ⊢ A ∈ ℝ → −∞ < A
3 1 2 syl ⊢ φ → −∞ < A