Description: Closure law for reciprocal. (Contributed by Mario Carneiro, 27-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypotheses | redivcld.1 | |- ( ph -> A e. RR ) |
|
rereccld.2 | |- ( ph -> A =/= 0 ) |
||
Assertion | rereccld | |- ( ph -> ( 1 / A ) e. RR ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | redivcld.1 | |- ( ph -> A e. RR ) |
|
2 | rereccld.2 | |- ( ph -> A =/= 0 ) |
|
3 | rereccl | |- ( ( A e. RR /\ A =/= 0 ) -> ( 1 / A ) e. RR ) |
|
4 | 1 2 3 | syl2anc | |- ( ph -> ( 1 / A ) e. RR ) |