This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: A power of an extended metric space is an extended metric space. (Contributed by Mario Carneiro, 28-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | pwsms.y | ⊢ 𝑌 = ( 𝑅 ↑s 𝐼 ) | |
| Assertion | pwsxms | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → 𝑌 ∈ ∞MetSp ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | pwsms.y | ⊢ 𝑌 = ( 𝑅 ↑s 𝐼 ) | |
| 2 | eqid | ⊢ ( Scalar ‘ 𝑅 ) = ( Scalar ‘ 𝑅 ) | |
| 3 | 1 2 | pwsval | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → 𝑌 = ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼 × { 𝑅 } ) ) ) |
| 4 | fvexd | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → ( Scalar ‘ 𝑅 ) ∈ V ) | |
| 5 | simpr | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → 𝐼 ∈ Fin ) | |
| 6 | fconst6g | ⊢ ( 𝑅 ∈ ∞MetSp → ( 𝐼 × { 𝑅 } ) : 𝐼 ⟶ ∞MetSp ) | |
| 7 | 6 | adantr | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → ( 𝐼 × { 𝑅 } ) : 𝐼 ⟶ ∞MetSp ) |
| 8 | eqid | ⊢ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼 × { 𝑅 } ) ) = ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼 × { 𝑅 } ) ) | |
| 9 | 8 | prdsxms | ⊢ ( ( ( Scalar ‘ 𝑅 ) ∈ V ∧ 𝐼 ∈ Fin ∧ ( 𝐼 × { 𝑅 } ) : 𝐼 ⟶ ∞MetSp ) → ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼 × { 𝑅 } ) ) ∈ ∞MetSp ) |
| 10 | 4 5 7 9 | syl3anc | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼 × { 𝑅 } ) ) ∈ ∞MetSp ) |
| 11 | 3 10 | eqeltrd | ⊢ ( ( 𝑅 ∈ ∞MetSp ∧ 𝐼 ∈ Fin ) → 𝑌 ∈ ∞MetSp ) |