Description: Any odd Goldbach number is positive. (Contributed by AV, 26-Jul-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | gbopos | |- ( Z e. GoldbachOdd -> Z e. NN ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | gbogbow | |- ( Z e. GoldbachOdd -> Z e. GoldbachOddW ) |
|
2 | gbowpos | |- ( Z e. GoldbachOddW -> Z e. NN ) |
|
3 | 1 2 | syl | |- ( Z e. GoldbachOdd -> Z e. NN ) |