Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Alexander van der Vekens
Even and odd numbers
Alternate definitions using the "modulo" operation
zefldiv2ALTV
Metamath Proof Explorer
Description: The floor of an even number divided by 2 is equal to the even number
divided by 2. (Contributed by AV , 7-Jun-2020) (Revised by AV , 18-Jun-2020)
Ref
Expression
Assertion
zefldiv2ALTV
⊢ ( 𝑁 ∈ Even → ( ⌊ ‘ ( 𝑁 / 2 ) ) = ( 𝑁 / 2 ) )
Proof
Step
Hyp
Ref
Expression
1
evendiv2z
⊢ ( 𝑁 ∈ Even → ( 𝑁 / 2 ) ∈ ℤ )
2
flid
⊢ ( ( 𝑁 / 2 ) ∈ ℤ → ( ⌊ ‘ ( 𝑁 / 2 ) ) = ( 𝑁 / 2 ) )
3
1 2
syl
⊢ ( 𝑁 ∈ Even → ( ⌊ ‘ ( 𝑁 / 2 ) ) = ( 𝑁 / 2 ) )