Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Alexander van der Vekens
Even and odd numbers
Definitions and basic properties
evenz
Next ⟩
oddz
Metamath Proof Explorer
Ascii
Structured
Theorem
evenz
Description:
An even number is an integer.
(Contributed by
AV
, 14-Jun-2020)
Ref
Expression
Assertion
evenz
⊢
(
𝑍
∈ Even →
𝑍
∈ ℤ )
Proof
Step
Hyp
Ref
Expression
1
iseven
⊢
(
𝑍
∈ Even ↔ (
𝑍
∈ ℤ ∧ (
𝑍
/ 2 ) ∈ ℤ ) )
2
1
simplbi
⊢
(
𝑍
∈ Even →
𝑍
∈ ℤ )