Description: Base set of a subring algebra. (Contributed by Stefan O'Rear, 27-Nov-2014) (Revised by Mario Carneiro, 4-Oct-2015) (Revised by Thierry Arnoux, 16-Jun-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | srapart.a | |- ( ph -> A = ( ( subringAlg ` W ) ` S ) ) |
|
| srapart.s | |- ( ph -> S C_ ( Base ` W ) ) |
||
| Assertion | srabase | |- ( ph -> ( Base ` W ) = ( Base ` A ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | srapart.a | |- ( ph -> A = ( ( subringAlg ` W ) ` S ) ) |
|
| 2 | srapart.s | |- ( ph -> S C_ ( Base ` W ) ) |
|
| 3 | df-base | |- Base = Slot 1 |
|
| 4 | 1nn | |- 1 e. NN |
|
| 5 | 1lt5 | |- 1 < 5 |
|
| 6 | 5 | orci | |- ( 1 < 5 \/ 8 < 1 ) |
| 7 | 1 2 3 4 6 | sralem | |- ( ph -> ( Base ` W ) = ( Base ` A ) ) |