Description: 2 is not an odd number. (Contributed by AV, 3-Feb-2020) (Revised by AV, 18-Jun-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | 2noddALTV | ⊢ 2 ∉ Odd |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2evenALTV | ⊢ 2 ∈ Even | |
2 | df-nel | ⊢ ( 2 ∉ Odd ↔ ¬ 2 ∈ Odd ) | |
3 | 2z | ⊢ 2 ∈ ℤ | |
4 | zeo2ALTV | ⊢ ( 2 ∈ ℤ → ( 2 ∈ Even ↔ ¬ 2 ∈ Odd ) ) | |
5 | 4 | bicomd | ⊢ ( 2 ∈ ℤ → ( ¬ 2 ∈ Odd ↔ 2 ∈ Even ) ) |
6 | 3 5 | ax-mp | ⊢ ( ¬ 2 ∈ Odd ↔ 2 ∈ Even ) |
7 | 2 6 | bitri | ⊢ ( 2 ∉ Odd ↔ 2 ∈ Even ) |
8 | 1 7 | mpbir | ⊢ 2 ∉ Odd |