Description: A number that sums to itself is zero. Compare addid0 , readdid1addid2d . (Contributed by SN, 5-May-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | sn-addid0.a | |- ( ph -> A e. CC ) |
|
sn-addid0.1 | |- ( ph -> ( A + A ) = A ) |
||
Assertion | sn-addid0 | |- ( ph -> A = 0 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sn-addid0.a | |- ( ph -> A e. CC ) |
|
2 | sn-addid0.1 | |- ( ph -> ( A + A ) = A ) |
|
3 | sn-addid1 | |- ( A e. CC -> ( A + 0 ) = A ) |
|
4 | 1 3 | syl | |- ( ph -> ( A + 0 ) = A ) |
5 | 2 4 | eqtr4d | |- ( ph -> ( A + A ) = ( A + 0 ) ) |
6 | 0cnd | |- ( ph -> 0 e. CC ) |
|
7 | 1 1 6 | sn-addcand | |- ( ph -> ( ( A + A ) = ( A + 0 ) <-> A = 0 ) ) |
8 | 5 7 | mpbid | |- ( ph -> A = 0 ) |