Description: If a number is zero, its square is zero. Deduction form of sq0i . Converse of sqeq0d . (Contributed by David Moews, 28-Feb-2017)
Ref | Expression | ||
---|---|---|---|
Hypothesis | sq0id.1 | |- ( ph -> A = 0 ) |
|
Assertion | sq0id | |- ( ph -> ( A ^ 2 ) = 0 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sq0id.1 | |- ( ph -> A = 0 ) |
|
2 | sq0i | |- ( A = 0 -> ( A ^ 2 ) = 0 ) |
|
3 | 1 2 | syl | |- ( ph -> ( A ^ 2 ) = 0 ) |