Description: A 1-dimensional subspace is an atom. (Contributed by NM, 22-Jul-2001) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | h1datom | |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sseq1 | |
|
| 2 | eqeq1 | |
|
| 3 | eqeq1 | |
|
| 4 | 2 3 | orbi12d | |
| 5 | 1 4 | imbi12d | |
| 6 | sneq | |
|
| 7 | 6 | fveq2d | |
| 8 | 7 | fveq2d | |
| 9 | 8 | sseq2d | |
| 10 | 8 | eqeq2d | |
| 11 | 10 | orbi1d | |
| 12 | 9 11 | imbi12d | |
| 13 | h0elch | |
|
| 14 | 13 | elimel | |
| 15 | ifhvhv0 | |
|
| 16 | 14 15 | h1datomi | |
| 17 | 5 12 16 | dedth2h | |