Description: 0 is a left identity for extended real addition. (Contributed by Glauco Siliprandi, 17-Aug-2020)
Ref | Expression | ||
---|---|---|---|
Hypothesis | xaddid2d.1 | |- ( ph -> A e. RR* ) |
|
Assertion | xaddid2d | |- ( ph -> ( 0 +e A ) = A ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xaddid2d.1 | |- ( ph -> A e. RR* ) |
|
2 | xaddid2 | |- ( A e. RR* -> ( 0 +e A ) = A ) |
|
3 | 1 2 | syl | |- ( ph -> ( 0 +e A ) = A ) |