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Description: No even integer equals an odd integer (i.e. no integer can be both even and odd). Exercise 10(a) of Apostol p. 28. (Contributed by NM, 31-Jul-2004) (Revised by AV, 16-Jun-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | zneoALTV | ⊢ ( ( 𝐴 ∈ Even ∧ 𝐵 ∈ Odd ) → 𝐴 ≠ 𝐵 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | oddneven | ⊢ ( 𝐵 ∈ Odd → ¬ 𝐵 ∈ Even ) | |
| 2 | nelne2 | ⊢ ( ( 𝐴 ∈ Even ∧ ¬ 𝐵 ∈ Even ) → 𝐴 ≠ 𝐵 ) | |
| 3 | 1 2 | sylan2 | ⊢ ( ( 𝐴 ∈ Even ∧ 𝐵 ∈ Odd ) → 𝐴 ≠ 𝐵 ) |