Description: An even Goldbach number is even. (Contributed by AV, 25-Jul-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | gbeeven | |- ( Z e. GoldbachEven -> Z e. Even ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | isgbe | |- ( Z e. GoldbachEven <-> ( Z e. Even /\ E. p e. Prime E. q e. Prime ( p e. Odd /\ q e. Odd /\ Z = ( p + q ) ) ) ) | |
| 2 | 1 | simplbi | |- ( Z e. GoldbachEven -> Z e. Even ) |