Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Alexander van der Vekens
Even and odd numbers
Theorems of AV's mathbox revised
2noddALTV
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nn0o1gt2ALTV
Metamath Proof Explorer
Ascii
Unicode
Theorem
2noddALTV
Description:
2 is not an odd number.
(Contributed by
AV
, 3-Feb-2020)
(Revised by
AV
, 18-Jun-2020)
Ref
Expression
Assertion
2noddALTV
⊢
2
∉
Odd
Proof
Step
Hyp
Ref
Expression
1
2evenALTV
⊢
2
∈
Even
2
df-nel
⊢
2
∉
Odd
↔
¬
2
∈
Odd
3
2z
⊢
2
∈
ℤ
4
zeo2ALTV
⊢
2
∈
ℤ
→
2
∈
Even
↔
¬
2
∈
Odd
5
4
bicomd
⊢
2
∈
ℤ
→
¬
2
∈
Odd
↔
2
∈
Even
6
3
5
ax-mp
⊢
¬
2
∈
Odd
↔
2
∈
Even
7
2
6
bitri
⊢
2
∉
Odd
↔
2
∈
Even
8
1
7
mpbir
⊢
2
∉
Odd