Description: "Reverse" second Peano postulate analogue for complex numbers: A complex number minus 1 is a complex number. (Contributed by Alexander van der Vekens, 18-Mar-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | peano2cnm | ⊢ ( 𝑁 ∈ ℂ → ( 𝑁 − 1 ) ∈ ℂ ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ax-1cn | ⊢ 1 ∈ ℂ | |
| 2 | subcl | ⊢ ( ( 𝑁 ∈ ℂ ∧ 1 ∈ ℂ ) → ( 𝑁 − 1 ) ∈ ℂ ) | |
| 3 | 1 2 | mpan2 | ⊢ ( 𝑁 ∈ ℂ → ( 𝑁 − 1 ) ∈ ℂ ) |