Description: Zero is a complex number. See also 0cnALT . (Contributed by NM, 19-Feb-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0cn | |- 0 e. CC |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ax-i2m1 | |- ( ( _i x. _i ) + 1 ) = 0 |
|
| 2 | ax-icn | |- _i e. CC |
|
| 3 | mulcl | |- ( ( _i e. CC /\ _i e. CC ) -> ( _i x. _i ) e. CC ) |
|
| 4 | 2 2 3 | mp2an | |- ( _i x. _i ) e. CC |
| 5 | ax-1cn | |- 1 e. CC |
|
| 6 | addcl | |- ( ( ( _i x. _i ) e. CC /\ 1 e. CC ) -> ( ( _i x. _i ) + 1 ) e. CC ) |
|
| 7 | 4 5 6 | mp2an | |- ( ( _i x. _i ) + 1 ) e. CC |
| 8 | 1 7 | eqeltrri | |- 0 e. CC |