Description: The multiplication operation of the ring of integers. (Contributed by Thierry Arnoux, 1-Nov-2017) (Revised by AV, 9-Jun-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | zringmulr | |- x. = ( .r ` ZZring ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | zex | |- ZZ e. _V | |
| 2 | df-zring | |- ZZring = ( CCfld |`s ZZ ) | |
| 3 | cnfldmul | |- x. = ( .r ` CCfld ) | |
| 4 | 2 3 | ressmulr | |- ( ZZ e. _V -> x. = ( .r ` ZZring ) ) | 
| 5 | 1 4 | ax-mp | |- x. = ( .r ` ZZring ) |