Description: Multiplication of a number and its reciprocal. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | div1d.1 | |- ( ph -> A e. CC ) |
|
| reccld.2 | |- ( ph -> A =/= 0 ) |
||
| Assertion | recid2d | |- ( ph -> ( ( 1 / A ) x. A ) = 1 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | div1d.1 | |- ( ph -> A e. CC ) |
|
| 2 | reccld.2 | |- ( ph -> A =/= 0 ) |
|
| 3 | recid2 | |- ( ( A e. CC /\ A =/= 0 ) -> ( ( 1 / A ) x. A ) = 1 ) |
|
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( ( 1 / A ) x. A ) = 1 ) |