Description: The adjoined complex number is an extended integer. (Contributed by AV, 25-Oct-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | adcnellaz | |- ( S e. CC -> S e. ( Z[]l ` S ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | mullid | |- ( S e. CC -> ( 1 x. S ) = S ) |
|
| 2 | 1z | |- 1 e. ZZ |
|
| 3 | adcnmulzlaz | |- ( ( S e. CC /\ 1 e. ZZ ) -> ( 1 x. S ) e. ( Z[]l ` S ) ) |
|
| 4 | 2 3 | mpan2 | |- ( S e. CC -> ( 1 x. S ) e. ( Z[]l ` S ) ) |
| 5 | 1 4 | eqeltrrd | |- ( S e. CC -> S e. ( Z[]l ` S ) ) |