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SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Alexander van der Vekens
Number theory (extension 2)
Goldbach's conjectures
gbopos
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gbegt5
Metamath Proof Explorer
Ascii
Unicode
Theorem
gbopos
Description:
Any odd Goldbach number is positive.
(Contributed by
AV
, 26-Jul-2020)
Ref
Expression
Assertion
gbopos
⊢
Z
∈
GoldbachOdd
→
Z
∈
ℕ
Proof
Step
Hyp
Ref
Expression
1
gbogbow
⊢
Z
∈
GoldbachOdd
→
Z
∈
GoldbachOddW
2
gbowpos
⊢
Z
∈
GoldbachOddW
→
Z
∈
ℕ
3
1
2
syl
⊢
Z
∈
GoldbachOdd
→
Z
∈
ℕ