Metamath Proof Explorer


Theorem nneoALTV

Description: A positive integer is even or odd but not both. (Contributed by NM, 1-Jan-2006) (Revised by AV, 19-Jun-2020)

Ref Expression
Assertion nneoALTV ( 𝑁 ∈ ℕ → ( 𝑁 ∈ Even ↔ ¬ 𝑁 ∈ Odd ) )

Proof

Step Hyp Ref Expression
1 nnz ( 𝑁 ∈ ℕ → 𝑁 ∈ ℤ )
2 zeo2ALTV ( 𝑁 ∈ ℤ → ( 𝑁 ∈ Even ↔ ¬ 𝑁 ∈ Odd ) )
3 1 2 syl ( 𝑁 ∈ ℕ → ( 𝑁 ∈ Even ↔ ¬ 𝑁 ∈ Odd ) )