Description: Closure of the multiplication operation of a ring. (Contributed by SN, 29-Jul-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ringcld.b | |- B = ( Base ` R ) | |
| ringcld.t | |- .x. = ( .r ` R ) | ||
| ringcld.r | |- ( ph -> R e. Ring ) | ||
| ringcld.x | |- ( ph -> X e. B ) | ||
| ringcld.y | |- ( ph -> Y e. B ) | ||
| Assertion | ringcld | |- ( ph -> ( X .x. Y ) e. B ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ringcld.b | |- B = ( Base ` R ) | |
| 2 | ringcld.t | |- .x. = ( .r ` R ) | |
| 3 | ringcld.r | |- ( ph -> R e. Ring ) | |
| 4 | ringcld.x | |- ( ph -> X e. B ) | |
| 5 | ringcld.y | |- ( ph -> Y e. B ) | |
| 6 | 1 2 | ringcl | |- ( ( R e. Ring /\ X e. B /\ Y e. B ) -> ( X .x. Y ) e. B ) | 
| 7 | 3 4 5 6 | syl3anc | |- ( ph -> ( X .x. Y ) e. B ) |