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ELEMENTARY NUMBER THEORY
Elementary prime number theory
Specific prime numbers
8nprm
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9nprm
Metamath Proof Explorer
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Unicode
Theorem
8nprm
Description:
8 is not a prime number.
(Contributed by
Mario Carneiro
, 18-Feb-2014)
Ref
Expression
Assertion
8nprm
⊢
¬
8
∈
ℙ
Proof
Step
Hyp
Ref
Expression
1
4nn
⊢
4
∈
ℕ
2
2nn
⊢
2
∈
ℕ
3
1lt4
⊢
1
<
4
4
1lt2
⊢
1
<
2
5
4t2e8
⊢
4
⋅
2
=
8
6
1
2
3
4
5
nprmi
⊢
¬
8
∈
ℙ