Metamath Proof Explorer


Theorem xnn0xrnemnf

Description: The extended nonnegative integers are extended reals without negative infinity. (Contributed by AV, 10-Dec-2020)

Ref Expression
Assertion xnn0xrnemnf ⊢ A ∈ ℕ 0 * → A ∈ ℝ * ∧ A ≠ −∞

Proof

Step Hyp Ref Expression
1 xnn0xr ⊢ A ∈ ℕ 0 * → A ∈ ℝ *
2 xnn0nemnf ⊢ A ∈ ℕ 0 * → A ≠ −∞
3 1 2 jca ⊢ A ∈ ℕ 0 * → A ∈ ℝ * ∧ A ≠ −∞