Description: Closure law for real division. (Contributed by SN, 25-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | redivvald.a | |- ( ph -> A e. RR ) |
|
| redivvald.b | |- ( ph -> B e. RR ) |
||
| redivvald.z | |- ( ph -> B =/= 0 ) |
||
| Assertion | sn-redivcld | |- ( ph -> ( A /R B ) e. RR ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | redivvald.a | |- ( ph -> A e. RR ) |
|
| 2 | redivvald.b | |- ( ph -> B e. RR ) |
|
| 3 | redivvald.z | |- ( ph -> B =/= 0 ) |
|
| 4 | 1 2 3 | redivvald | |- ( ph -> ( A /R B ) = ( iota_ x e. RR ( B x. x ) = A ) ) |
| 5 | 1 2 3 | rediveud | |- ( ph -> E! x e. RR ( B x. x ) = A ) |
| 6 | riotacl | |- ( E! x e. RR ( B x. x ) = A -> ( iota_ x e. RR ( B x. x ) = A ) e. RR ) |
|
| 7 | 5 6 | syl | |- ( ph -> ( iota_ x e. RR ( B x. x ) = A ) e. RR ) |
| 8 | 4 7 | eqeltrd | |- ( ph -> ( A /R B ) e. RR ) |