Description: The base set of a subspace. (Contributed by NM, 10-Apr-2008) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | hhsssh2.1 | ||
| hhssba.2 | |||
| Assertion | hhssba | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | hhsssh2.1 | ||
| 2 | hhssba.2 | ||
| 3 | eqid | ||
| 4 | 3 1 | hhsst | |
| 5 | 2 4 | ax-mp | |
| 6 | 2 | shssii | |
| 7 | 3 1 5 6 | hhshsslem1 |