Description: 3 is an odd number. (Contributed by AV, 20-Jul-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3odd | |- 3 e. Odd | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 2evenALTV | |- 2 e. Even | |
| 2 | df-3 | |- 3 = ( 2 + 1 ) | |
| 3 | evenp1odd | |- ( 2 e. Even -> ( 2 + 1 ) e. Odd ) | |
| 4 | 2 3 | eqeltrid | |- ( 2 e. Even -> 3 e. Odd ) | 
| 5 | 1 4 | ax-mp | |- 3 e. Odd |