Metamath Proof Explorer


Theorem nn0nepnfd

Description: No standard nonnegative integer equals positive infinity, deduction form. (Contributed by AV, 10-Dec-2020)

Ref Expression
Hypothesis nn0xnn0d.1 ⊢ φ → A ∈ ℕ 0
Assertion nn0nepnfd ⊢ φ → A ≠ +∞

Proof

Step Hyp Ref Expression
1 nn0xnn0d.1 ⊢ φ → A ∈ ℕ 0
2 nn0nepnf ⊢ A ∈ ℕ 0 → A ≠ +∞
3 1 2 syl ⊢ φ → A ≠ +∞