Metamath Proof Explorer


Definition df-dim

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 ∈ V ↦ ∪ ( ♯ “ ( LBasis ‘ 𝑓 ) ) )

Detailed syntax breakdown

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 ⊢ ∪ ( ♯ “ ( LBasis ‘ 𝑓 ) )
9 1 2 8 cmpt ⊢ ( 𝑓 ∈ V ↦ ∪ ( ♯ “ ( LBasis ‘ 𝑓 ) ) )
10 0 9 wceq ⊢ dim = ( 𝑓 ∈ V ↦ ∪ ( ♯ “ ( LBasis ‘ 𝑓 ) ) )