Description: Closure of square. (Contributed by Mario Carneiro, 28-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | expcld.1 | |- ( ph -> A e. CC ) |
|
| Assertion | sqcld | |- ( ph -> ( A ^ 2 ) e. CC ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | expcld.1 | |- ( ph -> A e. CC ) |
|
| 2 | sqcl | |- ( A e. CC -> ( A ^ 2 ) e. CC ) |
|
| 3 | 1 2 | syl | |- ( ph -> ( A ^ 2 ) e. CC ) |