Description: Closure law for addition of reals. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | recnd.1 | |- ( ph -> A e. RR ) |
|
| readdcld.2 | |- ( ph -> B e. RR ) |
||
| Assertion | readdcld | |- ( ph -> ( A + B ) e. RR ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | recnd.1 | |- ( ph -> A e. RR ) |
|
| 2 | readdcld.2 | |- ( ph -> B e. RR ) |
|
| 3 | readdcl | |- ( ( A e. RR /\ B e. RR ) -> ( A + B ) e. RR ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( A + B ) e. RR ) |