Description: Define the dimension of a vector space as the cardinality of its bases. Note that by lvecdim , all bases are equinumerous. (Contributed by Thierry Arnoux, 6-May-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-dim | |- dim = ( f e. _V |-> U. ( # " ( LBasis ` f ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cldim | |- dim |
|
| 1 | vf | |- f |
|
| 2 | cvv | |- _V |
|
| 3 | chash | |- # |
|
| 4 | clbs | |- LBasis |
|
| 5 | 1 | cv | |- f |
| 6 | 5 4 | cfv | |- ( LBasis ` f ) |
| 7 | 3 6 | cima | |- ( # " ( LBasis ` f ) ) |
| 8 | 7 | cuni | |- U. ( # " ( LBasis ` f ) ) |
| 9 | 1 2 8 | cmpt | |- ( f e. _V |-> U. ( # " ( LBasis ` f ) ) ) |
| 10 | 0 9 | wceq | |- dim = ( f e. _V |-> U. ( # " ( LBasis ` f ) ) ) |