Description: Relationship between division and reciprocal. Theorem I.9 of Apostol p. 18. (Contributed by NM, 11-Oct-1999)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | divclz.1 | |- A e. CC | |
| divclz.2 | |- B e. CC | ||
| Assertion | divreczi | |- ( B =/= 0 -> ( A / B ) = ( A x. ( 1 / B ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | divclz.1 | |- A e. CC | |
| 2 | divclz.2 | |- B e. CC | |
| 3 | divrec | |- ( ( A e. CC /\ B e. CC /\ B =/= 0 ) -> ( A / B ) = ( A x. ( 1 / B ) ) ) | |
| 4 | 1 2 3 | mp3an12 | |- ( B =/= 0 -> ( A / B ) = ( A x. ( 1 / B ) ) ) |